Custom attributes adds attributes to the <form> HTML tag. Using it requires a bit of technical knowledge. Most of the users will never need this, it is just used rarely.

Adding custom attributes to forms

Go to add/edit form, And do as give in the screenshot below:

Add key-value as given below:

Adding custom attributes to form input fields:

1. Click on any of the input field in add/edit form screen.
2. Click on Element configuration.
3. There you’ll find “Add custom attribute” button.