Unable to Post message to teams channel using Application permission

Question

Hi,

I've subscribed to team channel message using subscription api and i'm getting event for message but when i receive the event i want to post a message back to teams or update the same message i got a token using client credentials flow because i don't want to send message on user behalf.

But i'm unable to send message using application permission it give me the following error

{
"error": {
"code": "Forbidden",
"message": "Missing role permissions on the request. API requires one of 'Teamwork.Migrate.All, ChannelMessage.ReadWrite.All'. Roles on the request ''.",
"innerError": {
"date": "2022-01-25T09:19:59",
"request-id": "1b9d16cc-c40b-4c6a-8305-c6ca96983fd3",
"client-request-id": "1b9d16cc-c40b-4c6a-8305-c6ca96983fd3"
}
}
}

though I've the Teamwork.Migrate.All app permission
Question

1. Is it possible to send the message to team->channel->message using application permission ? if yes how to resolve the above error?
2. If not possible is there any other way which can achieve the following:
   I got an event for any message sent in the team channel and then i can reply or update the message using something like bot token ?

I know delegated permission is working but i don't want it on user behalf.

Thanks

Answer 1

Sending message in application context is ONLY supported when migration is in process. This is listed in the docs at https://learn.microsoft.com/en-us/graph/api/chatmessage-post?view=graph-rest-1.0&tabs=http#permissions. You can use bot to send a message in application context. Graph will not send you a bot token. Please refer to Bot documentation https://learn.microsoft.com/en-us/microsoftteams/platform/resources/bot-v3/bot-conversations/bots-conversations on how to send messages.