Hi,
Have you checked the add-ins on Microsoft 365?
Go to the Microsoft 365 admin center. Navigate to Settings > Integrated apps to see if the add-in is listed there.
Also note that you need to run Connect-OrganizationAddInService to connect to PowerShell by using your Microsoft 365 Global Admin credentials.
Best Regards,
Ian Xue
If the Answer is helpful, please click "Accept Answer" and upvote it.