It’s been a long awaited feature but as of version 5.11, the Advanced Custom Fields Pro license key can now be hard-coded using PHP into your WordPress configuration file. It’s simply a case of adding the following constant to your wp-config.php file or a config plugin of your own:
See the offical release notes here:
https://www.advancedcustomfields.com/blog/acf-5-11-release-rest-api/#license-key-improvements
