New way to login to Microsoft 365 tenant

[Adam-it]

What changed

Since 9.09 the PnP Management Shell was removed from all tenants. This was the default app that was used by CLI for Microsoft 365 to perform login. You may read more about this announcement and the reasoning behind it in this release blog post
https://pnp.github.io/blog/post/changes-pnp-management-shell-registration/

Using previous version of CLI

It is still possible to use any version of CLI for Microsoft 365 but now when performing login you need to pass the appId and tenant options either when running the command or as configs or as env variables.

Recommendation

It is highly recommended to upgrade to the latest major release - v9
The biggest changes made are those that address this new login behavior.
Now m365 setup command will allow you to create such an app in a matter of seconds. Please check the latest updates described in detail in this chapter https://pnp.github.io/blog/cli-for-microsoft-365/cli-for-microsoft-365-v9-0/#the-new-major-version-of-cli-for-microsoft-365--v9