Microsoft Graph API - 401 Unauthorized While Creating Chat - permissions

Question

I using the graph API v1.0 to create the one-to-One chat,but I found some account get 401 results.I check the Permission from the Api '/me/oauth2PermissionGrants',and I can find the 'Chat.Create' permission.
{
"#odata.context": "https://graph.microsoft.com/v1.0/$metadata#oauth2PermissionGrants",
"value": [
{
"clientId": "9fc4855b-4d7e-443b-a8f0-282690a55a73",
"consentType": "Principal",
"id": "W4XEn35NO0So8CgmkKVacwsSh1fUKDpBhq1AxEmfwg74z92MWfk9ToJPj-kyp8I8",
"principalId": "8cddcff8-f959-4e3d-824f-8fe932a7c23c",
"resourceId": "5787120b-28d4-413a-86ad-40c4499fc20e",
"scope": " offline_access openid profile email User.Read User.ReadWrite User.ReadBasic.All Chat.ReadWrite Chat.Create Presence.Read Presence.Read.All ChatMessage.Read ChatMessage.Send"
},
{
"clientId": "d39356e1-6d20-4d19-ad54-5278e19b94ec",
"consentType": "Principal",
"id": "4VaT0yBtGU2tVFJ44ZuU7AsSh1fUKDpBhq1AxEmfwg74z92MWfk9ToJPj-kyp8I8",
"principalId": "8cddcff8-f959-4e3d-824f-8fe932a7c23c",
"resourceId": "5787120b-28d4-413a-86ad-40c4499fc20e",
"scope": " offline_access openid profile email User.Read User.ReadWrite User.ReadBasic.All Chat.ReadWrite Chat.Create Presence.Read Presence.Read.All ChatMessage.Read ChatMessage.Send"
},
{
"clientId": "c81831d1-608e-43fa-abd4-3a09e523cb3c",
"consentType": "Principal",
"id": "0TEYyI5g-kOr1DoJ5SPLPAsSh1fUKDpBhq1AxEmfwg74z92MWfk9ToJPj-kyp8I8",
"principalId": "8cddcff8-f959-4e3d-824f-8fe932a7c23c",
"resourceId": "5787120b-28d4-413a-86ad-40c4499fc20e",
"scope": " offline_access openid profile email User.Read User.ReadWrite User.ReadBasic.All Chat.ReadWrite Chat.Create Presence.Read Presence.Read.All ChatMessage.Read ChatMessage.Send Files.Read Files.ReadWrite Files.Read.All Files.ReadWrite.All Sites.Read.All Sites.ReadWrite.All"
}
]
}
When I post "https://graph.microsoft.com/v1.0/chats",
set the body like this
{"members":[
{ "user#odata.bind":"https://graph.microsoft.com/v1.0/users('8cddcff8-f959-4e3d-824f-8fe932a7c23c')",
"#odata.type":"#microsoft.graph.aadUserConversationMember",
"roles":["owner"]},
{ "user#odata.bind":"https://graph.microsoft.com/v1.0/users('636f150e-f73c-44d6-be0c-4d543b2b4e5d')",
"#odata.type":"#microsoft.graph.aadUserConversationMember",
"roles":["owner"]
}
],
"chatType":"oneOnOne"
}
It response 401 Authentication failed
{
"error": {
"code": "Unauthorized",
"message": "Authentication failed.",
"innerError": {
"date": "2022-05-17T08:41:05",
"request-id": "de03512e-b97d-4229-b1ce-a73a61ed4f3d",
"client-request-id": "de03512e-b97d-4229-b1ce-a73a61ed4f3d"
}
}
}
When I replace another account's token & teamsUserId and try again ,It returns Ok!
Can you help me check the reason?

Answer 1

First of all check your app id secret and confirm
secondly check that the users you are trying to add have authorized your application.
thirdly check for access token you need scopes and permission according to the token you are sending to the graph
If you are using application token , use default scope and check whether you have added the chat.create application permission else if you are using token on behalf of user you need delegated permission for chat.create application