curl --request POST \
  --url https://api.getarbol.com/v1/conversations \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "phone": "<string>",
  "agentId": "<string>",
  "contactId": "<string>",
  "systemPromptOverride": "<string>",
  "greetingOverride": "<string>",
  "language": "<string>",
  "variables": {},
  "metadata": {}
}
'

{
  "error": {
    "code": "<string>",
    "message": "<string>",
    "details": {}
  },
  "requestId": "<string>"
}