There are a few steps to enable this process:
If you have the correct permissions on a site you will be able to access the 'Site Settings' App from within your Site Settings general area. To see how to access this area, please click here.
Once you have accessed the 'Site Settings' App, scroll down to the area titled "GDPR Signup" and click the option for "GDPR Sign Up Enabled". The options will then allow a title and description to be added.
Once enabled, all users will be forced to sign up in order to continue using the site. They will see the following option once they've successfully entered credentials to login to a site. Users will not be able to continue to use a site unless they accept the policy
A record of the date, time and the specified policy they signed up to is stored and displayed at the bottom of their User Profile as a read only value, indicating when they accepted the policy and what exactly they agreed to.