This behavior is by design in New Teams Client.
To interact with bot via azure portal, you need to have side loading of apps enabled in the tenant.
For classic Teams also, same behaviour will be implemented but we don't have exact ETA to share.
Reference docs:
Enable custom Teams apps and turn on custom app uploading: https://learn.microsoft.com/en-us/microsoftteams/platform/concepts/build-and-test/prepare-your-o365-tenant#enable-custom-teams-apps-and-turn-on-custom-app-uploading
Upload your app in Teams: https://learn.microsoft.com/en-us/microsoftteams/platform/concepts/deploy-and-publish/apps-upload
Please refer this thread: https://github.com/MicrosoftDocs/msteams-docs/issues/9743
Thanks,
Prasad Das
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