Manually override domain signup rules

We have set a domain verification rule Action for new signups, only email addresses with @domain.com is allowed to signup automatically. However, from time to time, we want to manually override this rule and manually from the Users panel in Auth0 dashboard add users with other email domains.

Right now we get this error when trying to do so:

Error! Sandbox Error: All Access Denied Error:

Any hints on how to achieve adding users manually would be greatly appreciated.