This filter can modify any part of the form configuration, including form settings or field settings. This filter enables you to modify forms saved in the database or load forms from the file system.
Forcing Caldera Forms Entry Saving On Or Off
Where Does This Code Go?
When using WordPress hooks to customize Caldera Forms or other plugins you should not modify the plugin files, or you will lose your changes when you update the plugin. Instead you should create a small plugin to hold the custom code. It's easy, learn how here.
Technically you can add the custom code to your theme's functions.php, but then you will not be able to change your theme and keep these customizations.