Teams message extension on outlook

Hi PedroKlein - Thanks for raising the query.
We will look into it and let you know the updates.

Update: To make your message extension appear only in Microsoft Teams and not in Outlook, follow these steps:

Update Your App Manifest
1. Open your app manifest file.
2. Update the $schema and manifestVersion to ensure the extension runs only in Teams:

{
  "$schema" : "https://developer.microsoft.com/json-schemas/teams/v1.16/MicrosoftTeams.schema.json",
  "manifestVersion" : "1.16"
}

Remove Microsoft 365 Channel Configuration

1. Go to the Microsoft Azure portal or Bot Framework portal.
2. Navigate to your bot resource.
3. In the Settings section, go to Channels.
4. Under Available channels, make sure to remove the Microsoft 365 channel configuration if enabled.
5. Save the changes to ensure that your message extension is no longer available in Outlook.

Re-upload your updated app package into Teams and verify the extension is no longer visible in Outlook. If you have any further questions or need more assistance, feel free to ask!

For more information, you can refer to the Microsoft Teams platform documentation.