Say https://www.eyewearuk.com/, the theme outputs all the static file to:
<link rel=”stylesheet” type=”text/css” media=”all” href=”https://www.eyewearuk.com/pub/static/version1618304858/frontend/Mgs/cheapglasses/en_US/mage/calendar.css” />
<link rel=”stylesheet” type=”text/css” media=”all” href=”https://www.eyewearuk.com/pub/static/version1618304858/frontend/Mgs/cheapglasses/en_US/MGS_Mpanel/css/owl.carousel.css” />
<link rel=”stylesheet” type=”text/css” media=”all” href=”https://www.eyewearuk.com/pub/static/version1618304858/frontend/Mgs/cheapglasses/en_US/MGS_Mpanel/css/owl.theme.min.css” />
<link rel=”stylesheet” type=”text/css” media=”all” href=”https://www.eyewearuk.com/pub/static/version1618304858/frontend/Mgs/cheapglasses/en_US/MGS_Mpanel/css/animate.css” />
<link rel=”stylesheet” type=”text/css” media=”all” href=”https://www.eyewearuk.com/pub/static/version1618304858/frontend/Mgs/cheapglasses/en_US/MGS_Mpanel/css/magnific-popup.css” />
<link rel=”stylesheet” type=”text/css” media=”all” href=”https://www.eyewearuk.com/pub/static/version1618304858/frontend/Mgs/cheapglasses/en_US/Magento_Swatches/css/swatches.css” />
<link rel=”stylesheet” type=”text/css” media=”all” href=”https://www.eyewearuk.com/pub/static/version1618304858/frontend/Mgs/cheapglasses/en_US/MGS_GDPR/css/gdpr.css” />
<link rel=”stylesheet” type=”text/css” media=”all” href=”https://www.eyewearuk.com/pub/static/version1618304858/frontend/Mgs/cheapglasses/en_US/MGS_Lookbook/css/styles.css” />
<link rel=”stylesheet” type=”text/css” media=”all” href=”https://www.eyewearuk.com/pub/static/version1618304858/frontend/Mgs/cheapglasses/en_US/MGS_Mmegamenu/css/megamenu.css” />
<link rel=”stylesheet” type=”text/css” media=”all” href=”https://www.eyewearuk.com/pub/static/version1618304858/frontend/Mgs/cheapglasses/en_US/MGS_Promobanners/css/promobanners.css” />
<link rel=”stylesheet” type=”text/css” media=”all” href=”https://www.eyewearuk.com/pub/static/version1618304858/frontend/Mgs/cheapglasses/en_US/Mageplaza_Core/css/owl.carousel.css” />
<link rel=”stylesheet” type=”text/css” media=”all” href=”https://www.eyewearuk.com/pub/static/version1618304858/frontend/Mgs/cheapglasses/en_US/Mageplaza_Core/css/owl.theme.css” />
<link rel=”stylesheet” type=”text/css” media=”all” href=”https://www.eyewearuk.com/pub/static/version1618304858/frontend/Mgs/cheapglasses/en_US/css/bootstrap.min.css” />
<link rel=”stylesheet” type=”text/css” media=”all” href=”https://www.eyewearuk.com/pub/static/version1618304858/frontend/Mgs/cheapglasses/en_US/css/font-awesome.css” />
<link rel=”stylesheet” type=”text/css” media=”all” href=”https://www.eyewearuk.com/pub/static/version1618304858/frontend/Mgs/cheapglasses/en_US/css/pe-icon-7-stroke.css” />
<link rel=”stylesheet” type=”text/css” media=”all” href=”https://www.eyewearuk.com/pub/static/version1618304858/frontend/Mgs/cheapglasses/en_US/css/menu.css” />
<link rel=”stylesheet” type=”text/css” media=”all” href=”https://www.eyewearuk.com/pub/static/version1618304858/frontend/Mgs/cheapglasses/en_US/css/theme_default.css” />
<link rel=”stylesheet” type=”text/css” media=”all” href=”https://www.eyewearuk.com/pub/static/version1618304858/frontend/Mgs/cheapglasses/en_US/css/theme.css” />
<link rel=”stylesheet” type=”text/css” media=”all” href=”https://www.eyewearuk.com/pub/static/version1618304858/frontend/Mgs/cheapglasses/en_US/css/responsive.css” />
<link rel=”stylesheet” type=”text/css” media=”all” href=”https://www.eyewearuk.com/pub/static/version1618304858/frontend/Mgs/cheapglasses/en_US/MGS_Mpanel/css/color.css” />
<link rel=”stylesheet” type=”text/css” media=”all” href=”https://www.eyewearuk.com/pub/static/version1618304858/frontend/Mgs/cheapglasses/en_US/css/custom.css” />
<link rel=”stylesheet” type=”text/css” media=”all” href=”https://www.eyewearuk.com/pub/static/version1618304858/frontend/Mgs/cheapglasses/en_US/MGS_Mpanel/css/default.css” />
<link rel=”stylesheet” type=”text/css” media=”all” href=”https://www.eyewearuk.com/pub/static/version1618304858/frontend/Mgs/cheapglasses/en_US/MGS_InstantSearch/css/styles.css” />
<link rel=”stylesheet” type=”text/css” media=”all” href=”https://www.eyewearuk.com/pub/static/version1618304858/frontend/Mgs/cheapglasses/en_US/Mageplaza_SocialLogin/css/style.css” />
<link rel=”stylesheet” type=”text/css” media=”all” href=”https://www.eyewearuk.com/pub/static/version1618304858/frontend/Mgs/cheapglasses/en_US/Mageplaza_Core/css/grid-mageplaza.css” />
<link rel=”stylesheet” type=”text/css” media=”all” href=”https://www.eyewearuk.com/pub/static/version1618304858/frontend/Mgs/cheapglasses/en_US/Amasty_SeoToolKit/css/source/mkcss/amseokit.css” />
<link rel=”stylesheet” type=”text/css” media=”all” href=”https://www.eyewearuk.com/pub/static/version1618304858/frontend/Mgs/cheapglasses/en_US/MGS_Brand/css/mgs_brand.css” />
How to let the code be:
<link rel=”stylesheet” type=”text/css” media=”all” href=”https://www.eyewearuk.com/pub/static/version1618304858/frontend/Mgs/cheapglasses/en_GB/mage/calendar.css” />
<link rel=”stylesheet” type=”text/css” media=”all” href=”https://www.eyewearuk.com/pub/static/version1618304858/frontend/Mgs/cheapglasses/en_GB/MGS_Mpanel/css/owl.carousel.css” />
<link rel=”stylesheet” type=”text/css” media=”all” href=”https://www.eyewearuk.com/pub/static/version1618304858/frontend/Mgs/cheapglasses/en_GB/MGS_Mpanel/css/owl.theme.min.css” />
<link rel=”stylesheet” type=”text/css” media=”all” href=”https://www.eyewearuk.com/pub/static/version1618304858/frontend/Mgs/cheapglasses/en_GB/MGS_Mpanel/css/animate.css” />
<link rel=”stylesheet” type=”text/css” media=”all” href=”https://www.eyewearuk.com/pub/static/version1618304858/frontend/Mgs/cheapglasses/en_GB/MGS_Mpanel/css/magnific-popup.css” />
<link rel=”stylesheet” type=”text/css” media=”all” href=”https://www.eyewearuk.com/pub/static/version1618304858/frontend/Mgs/cheapglasses/en_GB/Magento_Swatches/css/swatches.css” />
<link rel=”stylesheet” type=”text/css” media=”all” href=”https://www.eyewearuk.com/pub/static/version1618304858/frontend/Mgs/cheapglasses/en_GB/MGS_GDPR/css/gdpr.css” />
<link rel=”stylesheet” type=”text/css” media=”all” href=”https://www.eyewearuk.com/pub/static/version1618304858/frontend/Mgs/cheapglasses/en_GB/MGS_Lookbook/css/styles.css” />
<link rel=”stylesheet” type=”text/css” media=”all” href=”https://www.eyewearuk.com/pub/static/version1618304858/frontend/Mgs/cheapglasses/en_GB/MGS_Mmegamenu/css/megamenu.css” />
<link rel=”stylesheet” type=”text/css” media=”all” href=”https://www.eyewearuk.com/pub/static/version1618304858/frontend/Mgs/cheapglasses/en_GB/MGS_Promobanners/css/promobanners.css” />
<link rel=”stylesheet” type=”text/css” media=”all” href=”https://www.eyewearuk.com/pub/static/version1618304858/frontend/Mgs/cheapglasses/en_GB/Mageplaza_Core/css/owl.carousel.css” />
<link rel=”stylesheet” type=”text/css” media=”all” href=”https://www.eyewearuk.com/pub/static/version1618304858/frontend/Mgs/cheapglasses/en_GB/Mageplaza_Core/css/owl.theme.css” />
<link rel=”stylesheet” type=”text/css” media=”all” href=”https://www.eyewearuk.com/pub/static/version1618304858/frontend/Mgs/cheapglasses/en_GB/css/bootstrap.min.css” />
<link rel=”stylesheet” type=”text/css” media=”all” href=”https://www.eyewearuk.com/pub/static/version1618304858/frontend/Mgs/cheapglasses/en_GB/css/font-awesome.css” />
<link rel=”stylesheet” type=”text/css” media=”all” href=”https://www.eyewearuk.com/pub/static/version1618304858/frontend/Mgs/cheapglasses/en_GB/css/pe-icon-7-stroke.css” />
<link rel=”stylesheet” type=”text/css” media=”all” href=”https://www.eyewearuk.com/pub/static/version1618304858/frontend/Mgs/cheapglasses/en_GB/css/menu.css” />
<link rel=”stylesheet” type=”text/css” media=”all” href=”https://www.eyewearuk.com/pub/static/version1618304858/frontend/Mgs/cheapglasses/en_GB/css/theme_default.css” />
<link rel=”stylesheet” type=”text/css” media=”all” href=”https://www.eyewearuk.com/pub/static/version1618304858/frontend/Mgs/cheapglasses/en_GB/css/theme.css” />
<link rel=”stylesheet” type=”text/css” media=”all” href=”https://www.eyewearuk.com/pub/static/version1618304858/frontend/Mgs/cheapglasses/en_GB/css/responsive.css” />
<link rel=”stylesheet” type=”text/css” media=”all” href=”https://www.eyewearuk.com/pub/static/version1618304858/frontend/Mgs/cheapglasses/en_GB/MGS_Mpanel/css/color.css” />
<link rel=”stylesheet” type=”text/css” media=”all” href=”https://www.eyewearuk.com/pub/static/version1618304858/frontend/Mgs/cheapglasses/en_GB/css/custom.css” />
<link rel=”stylesheet” type=”text/css” media=”all” href=”https://www.eyewearuk.com/pub/static/version1618304858/frontend/Mgs/cheapglasses/en_GB/MGS_Mpanel/css/default.css” />
<link rel=”stylesheet” type=”text/css” media=”all” href=”https://www.eyewearuk.com/pub/static/version1618304858/frontend/Mgs/cheapglasses/en_GB/MGS_InstantSearch/css/styles.css” />
<link rel=”stylesheet” type=”text/css” media=”all” href=”https://www.eyewearuk.com/pub/static/version1618304858/frontend/Mgs/cheapglasses/en_GB/Mageplaza_SocialLogin/css/style.css” />
<link rel=”stylesheet” type=”text/css” media=”all” href=”https://www.eyewearuk.com/pub/static/version1618304858/frontend/Mgs/cheapglasses/en_GB/Mageplaza_Core/css/grid-mageplaza.css” />
<link rel=”stylesheet” type=”text/css” media=”all” href=”https://www.eyewearuk.com/pub/static/version1618304858/frontend/Mgs/cheapglasses/en_GB/Amasty_SeoToolKit/css/source/mkcss/amseokit.css” />
<link rel=”stylesheet” type=”text/css” media=”all” href=”https://www.eyewearuk.com/pub/static/version1618304858/frontend/Mgs/cheapglasses/en_GB/MGS_Brand/css/mgs_brand.css” />
As we know, UK timezone should be set to Greenwich Mean Time (Europe/London).
Set Locale from Admin >> Store >> Configuration >> General >> General >> Locale Option >> Locale >> English //Here you have to select only one English locale
Static files should be generated based on the above locale setting, if multiple locale set then it will generate multiple static files as per locale
Set above configuration and run below command, It will generate only pub\static\frontend\VendorName\thmemeName\en_US
php bin/magento setup:upgrade
php bin/magento setup:static-content:deploy