curl --request POST \
  --url https://api.ravan.ai/api/v1/calling/create-call \
  --header 'Content-Type: application/json' \
  --header 'X-Api-Key: <api-key>' \
  --data '
{
  "type": "web_call",
  "agent_id": "<string>",
  "from_phone_number": "<string>",
  "to_phone_number": "<string>",
  "metadata": {},
  "prompt_dynamic_variables": {}
}
'

{
  "success": true,
  "message": "<string>",
  "data": {
    "url": "<string>",
    "access_token": "<string>",
    "session_id": "<string>"
  }
}