Calling a bot endpoint and answer

I built a bot in Teams which have the following Calling endpoint.

when the bot is called, i receive the following message at my Api endpoint via the "AnswerCall" method:

{
  "id": "1adecac7-2911-4335-8253-362c59694c56",
  "participants": [
    {
      "identity": "29:1IwDeUzZgQ07weRUHF187SDIUrN-pe6Q95bQMHq-uDoPHHA_RjxFHIy-Qa0BeTUDyLfpKNVQp6TmETTF6MqB3Rw",
      "participantId": "948a3788-0318-48ef-bd38-14d825f41d45",
      "endpointId": "da4303d8-e86b-44dc-9e1d-120db8a7b60e",
      "languageId": "en-US",
      "tenantId": "664f8a72-63a7-4e25-b660-c4dd7c962773",
      "region": "emea",
      "originator": true,
      "isHidden": false,
      "endPointType": "default"
    },
    {
      "identity": "28:a368f612-e639-42eb-b63e-1c7199f1433f",
      "participantId": "1adecac7-2911-4335-8253-362c59694c56",
      "endpointId": "00000000-0000-0000-0000-000000000000",
      "originator": false,
      "isHidden": false,
      "endPointType": "default"
    }
  ],
  "isMultiparty": false,
  "presentedModalityTypes": [
    "audio"
  ],
  "callState": "incoming",
  "tenantId": "664f8a72-63a7-4e25-b660-c4dd7c962773"
}

according to this documentation i should be able to answer or get the call by calling Graph API.

GET /app/calls/{id}

GET https://graph.microsoft.com/beta/app/calls/{id}

but i always receive the following error:

{
  "error": {
    "code": "BadRequest",
    "message": "Resource not found for the segment 'calls'.",
    "innerError": {
      "request-id": "886f8e9b-522f-40e0-a10f-ced9a054708e",
      "date": "2019-10-10T14:08:10"
    }
  }
}

The Question is:

am i using the correct call Id from the message?

"id": "1adecac7-2911-4335-8253-362c59694c56"

P.S: I can call other Graph API (Beta version) Methods like Get Users and it works. so i don't have any authentication problem. and also i set all the permission which is required for my app in AAD.

Thank you ,

E.A