I have a form that I have configured in Field Maps Designer, and it includes inputting emails and phone numbers. I have searched and searched, and not seen a way to control the input to these fields on form builder. I would like to throw an alert or not allow submission if the email address doesn't have an @ sign, or if the phone numbers are too long, etc.
The Arcade expression areas available only appear to provide control logic to whether or not the field is required, editable, visible, or to calculate an expression:

I just wanted to confirm that regex is not available through Field Maps form builder anywhere, and I am not just missing it? Note that I cannot use Survey123 for this particular project (not worth describing why), otherwise yes I would be using Survey123 Connect for this because I know that you can use regex there.