Form elements have a Form Check section to validate user inputs.
By default, it comes with a validator for required fields. By toggling Required, you can require the user to enter an input. If no input is entered, the error prompt will be shown.
You can also add validators, such as checking if the input is an email.
Select the check type. When Check Value is toggled on, the validator will be on. Type in what text to display when there's an error into Error prompt.