curl --request POST \
  --url https://rest-api.smsmngr.com/v1/whatsapp/registration \
  --header 'Content-Type: application/json' \
  --header 'x-api-key: <api-key>' \
  --data '
{
  "token": "eyJhbGciOi...",
  "waba_id": "1234567890",
  "code": "AQD...meta-oauth-code",
  "phone_number_id": "109876543210987",
  "client_id": "client-42",
  "description": "Official Acme Store WhatsApp",
  "email": "support@acme.example",
  "website": "https://acme.example"
}
'

{
  "success": true,
  "phone_number_id": "109876543210987",
  "phone_number": "420226633283"
}