You can use that filter in your functions, it will work if you change ‘name’ in what ever you’ve called your custom field. If you change it, yoast will read that field.
But here’s the problem, it will only read 1 custom field on 1 page. If you need to scan multiple acf, yoast only sees the first one defined in functions. We tried everything, adding multiple filters to our functions for each custom field separately, but it will ignore the other filters. Now the creators of acf say this is something yoast needs to fix (not sure if this attitude helps with promoting acf), so we wont find the answer here.
