Dynamics for Marketing makes adhering to GDPR much easier through the use of subscription centres. Dynamics for Marketing blocks you from sending out marketing emails, unless you provide an unsubscribe link. This blog post will show you how to manage your subscription centre and customise your unsubscribe form.
By default Dynamics for Marketing creates a subscription centre form and page. The page is listed as Default Marketing Page.

The first thing you will notice when opening the Default Marketing Page is that it is blank so your first step will be adding the Default Subscription Centre Form. To do this you will need to edit the Marketing Page and insert the Default Subscription Centre Form.
As you can see the default form is very plain but you have the option to edit this like you would with any other Marketing Form. First of all you need to open the Default Subscription Centre form.

I’ve added a logo, additional fields and made them required to give the form a more professional look. Upon hitting save your new form will automatically go live and this will be reflected on your Marketing Page.

To add your Subscription Centre Page to an email you need to open the editor, click inside a text box and create a link on a piece of text. I’ve decided to use the word Unsubscribe but if you prefer you can add the entire URL to the email.

You then need to click Assist Edit button

Choose Contextual and Content Settings.

Choose Property and Subscription Centre, then hit OK

This will change whatever word you highlighted into a link to your Subscription Centre Page.

Microsoft have their own in depth post, which covers every base of subscription centres and this can be accessed here: https://docs.microsoft.com/en-us/dynamics365/marketing/set-up-subscription-center