How can I add php code such as a table creation to my WP App Studio app?

Since version 5.3.0 WP App Studio has a php code area. This php code area is found in Settings page under Code tab. Here you can enter your php code for different needs such as creating tables , adding and calling WordPress filters and actions or any other plugin actions and filters to integrate with your app and/or WordPress. This code is added as an extra file in your app in generation time. Please do a syntax(lint) check before you add your code. If your code has any syntax error, your app won't generate and return an error.  This feature is supported on all ProDev plans and not included in FreeDev plan.