One of the requirements of GDPR is that you should get explicit consent from your subscribers. This feature will let you add a consent checkbox to your MailMunch opt-in forms.
Step 1: Create or Edit your opt-in form. Click on the Fields step.
Step 2: Click on Add New Field and the drop-down menu will display several field options that are available. Select the Subscriber Consent option or add a new field.
Step 4: The consent field will be added to your form!
Step 5: Once the subscribers have given explicit consent, you can see the proof of consent on their subscribers page.