curl --request POST \
  --url https://api.open.cx/phone/sip/agents/{phone_agent_id}/transfer-destinations \
  --header 'Content-Type: application/json' \
  --data '
{
  "destination_id": "3c90c3cc-0d44-4b50-8888-8dd25736052a",
  "create": {
    "name": "<string>",
    "type": "phone",
    "value": "<string>"
  }
}
'

{
  "destination_id": "3c90c3cc-0d44-4b50-8888-8dd25736052a"
}