curl --request POST \
  --url https://api.vzaps.com/instances/{id}/user/check \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "phone": [
    "<string>"
  ]
}
'

{
  "code": 200,
  "success": true,
  "data": {
    "users": [
      {
        "phone": "5511999999999",
        "exists": true,
        "jid": "5511999999999@s.whatsapp.net"
      }
    ]
  }
}