When you register for WiseStamp through your Google Workspace (G Suite) domain, you essentially enable the WiseStamp app on your G Suite Marketplace Apps list. Once you no longer have access to the G Suite apps, you will also no longer have access to your WiseStamp account.
What to do?
We'll need to delete the account you registered with while using Google Workspace (G Suite), and have you sign up again as an "Outlook" registered account. So that you don't lose your signature, we can copy your signature over to a test account, and then move it back to your new account after registering again. Just let us know that you've changed your domain provider and we'll walk you through the rest! Send us an email to email@example.com so we can get you started with this process ASAP.