curl --request PATCH \
  --url https://api.getoutbox.ai/settings/phone \
  --header 'Authorization: <api-key>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "phone_number_id": "<string>",
  "agent": "<string>",
  "sip_uri": "<string>",
  "sip_username": "<string>",
  "sip_password": "<string>"
}
'