Hi there,
You may need to change the Google font subset to one of the options:
latin
latin-ext
menu
greek
greek-ext
cyrillic
cyrillic-ext
vietnamese
arabic
khmer
lao
tamil
bengali
hindi
korean
You can set them like this:
add_filter('generate_fonts_subset','generate_change_fonts_subset');
function generate_change_fonts_subset()
{
return 'latin-ext';
}
Just replace the value with the proper subset for Polish.
Adding PHP: https://generatepress.com/knowledgebase/adding-php-functions/
Let me know if you need more info 🙂