curl --request PUT \
  --url https://api.open.cx/phone/sip/agents/{phone_agent_id}/inbound-numbers \
  --header 'Content-Type: application/json' \
  --data '
{
  "phone_number_ids": [
    "<string>"
  ]
}
'

[
  {
    "id": "<string>",
    "phone_number": "<string>",
    "status": "<string>"
  }
]