FORM AND GDPR

Hi

I want to create an opt in form for marketing and GDPR compliance. I want to send this to my customers via a link in an email. 

How do i cover the fact that there data will be stored in your system? 

JotForm is GDPR compliant - https://www.jotform.com/gdpr-compliance/ 

https://www.jotform.com/eu-safe-forms/