curl --request GET \
  --url https://api.upon-ai.com/api/v1/calls/{callId} \
  --header 'Authorization: Bearer <token>'

{
  "success": true,
  "call": {
    "callId": "<string>",
    "callType": "<string>",
    "status": "<string>",
    "agentId": "<string>",
    "agentVersion": 123,
    "metadata": {},
    "optOutSensitiveDataStorage": true,
    "accessToken": "<string>",
    "expiresAt": "2023-11-07T05:31:56Z",
    "webCallUrl": "<string>",
    "uponai_dynamic_variables": {}
  }
}