Microsoft App registrations have a maximum time period of 2 years. Generally, App registrations are 1 or less for most third party apps.

We have made it easy to address an expiring app registration for Phone System SSO

Log into the Control portal as a user with Admin rights, go to the specific account you need to access.

Once inside the account dashboard, go to Integrations, and Microsoft 365

Click on Re-Provision account

Click on the blue Sign in button and use an account on your Microsoft 365 tenant with Global Admin rights.