Unable to send notification to teams installed application users

This can happen if you might have misconfigured the identifier value for the application or sent your authentication request to the wrong tenant. 

1. Verify Application Identifier:

• Ensure that the correct appId or client id is being used in the manifest.json file. The botId should match the appId of the bot registration in Azure.
• Check the appId in the Azure portal under the bot registration to confirm it matches the one in the manifest.json file.

2. Check Application Installation:

• Make sure that the application has been installed by the administrator of the tenant or consented to by any user in the tenant.
• Verify that the app has been uploaded to the organization's App Catalog and is available for installation by users in the organization.

3. Add Required Permissions:

• Confirm if the required Microsoft Graph Application-level permissions 'TeamsAppInstallation.ReadWriteForUser.All' have been added to the Azure AD app registration associated with your bot.

4. Update App Settings:

• Ensure that the appsettings.json file contains the correct ids and secret details related to the bot registration in Azure.

Similar issue here: Message: AADSTS700016: Application with identifier not found in the directory (domain name). error logging into outlook calendar from web app - Microsoft Q&A
You can also refer:

Fix - AADSTS700016: Application not found or consented to by any user. (morgantechspace.com)

However, if you have any business critical issue which need immediate attention, please raise a support request here:  
https://docs.microsoft.com/en-us/microsoft-365/admin/get-help-support?view=o365-worldwide&tabs=online 

Thanks, 

Prasad Das

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