I’m using ACF 4 before and I’ve just bought ACF Pro today. ACF was installed in the wordpress theme before (not in plugins) and I’ve replaced it with ACF pro. Right now all the fields in the backend look wonky but it all works fine in the front-end. All the fields are hard-coded in the functions.php file (No XML or JSON). Is there a way I can fix or export the code for it to work with ACF pro?
You do not need to make any code changes, ACF Pro contains a compatibility patch and you will only need to follow the steps outlined here: https://www.advancedcustomfields.com/resources/upgrading-v4-v5/
Your v4 field types will then be compatible in the Pro version.