Adding new file in claim listing popup form

Good afternoon. I am preparing all form for GDPR law and I would need to add a check button for privacy policy in claim listing pop up form and save the content of it in the email we receive or in the claim listing area in order to be right with the GDPR law.

I have found how to do it for inquire form, and I have applied it to insert the check button, but I don´t know how can I sotore the value in the database to prove the client has approved our privacy policy. If it is not possible an alternative would be receive that fields in the admin notification email.

Thanks in advance