Can not access the community/admin console on our Acceptance/sandbox environment

Hello,

I just activated the 'Verint – MFA Plugin’ extension on our Acceptance/sandbox environment. However, since that I can no longer access the admin console or any other page within our community.

How can I undo or reverse this action? Or make sure I can access the admin console?

Note: The 'verify email' (/verifyemail?) page seems empty, therefore I can not verify my email address with a one time code.