curl --request POST \
  --url https://api.upon-ai.com/api/v1/calls/initiate \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "agentId": "<string>",
  "workspaceId": 123,
  "fromNumber": "<string>",
  "toNumber": "<string>",
  "customerName": "<string>",
  "carrierName": "<string>",
  "trunkName": "<string>",
  "overrideCid": "<string>",
  "customFromNumber": "<string>",
  "customStatusHookUrl": "<string>",
  "metadata": {},
  "uponai_dynamic_variables": {}
}
'

{
  "success": true,
  "call_sid": "<string>",
  "call": {
    "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": {}
    }
  }
}