I want to create a car website and I need to create the make and model fields. The mistake has been that I don’t know when a user chooses a brand to show the models of that specific brand. Where should I write the code that I show in this tutorial? https://www.bobz.co/dynamically-populate-select-fields-choice-in-advanced-custom-fields. in the functions.php of my theme? thanks
Yes, the PHP would go in functions.php. And the JS (jQuery) goes into a JS file in your theme directory that is enqueued (as that tutorial also explains).