My CiviCRM 5.56.1 runs on Drupal 7.
I try to set the default value for a custom field which is used for an Action.
I created the field in Admin -> Customized Data & Screen -> Custom Fields. The field
custom_76_-1 is shown in the form, and it works, I can change the current value. This is a date field showing a year-value only, and I'd like to set it's default value from current year to 3 years before (eg. in this year from 2022 to 2019). On the UI I can set a fix date, not a relative date.
buildForm() function runs earlier as the AJAX call, which creates the custom field, so the default value can't be set (is this true or do / understand I something wrong?).
Please advice me how can I set the field's default value.