How to send JSON raw data using volley

Question

I want to POST these field in backend but it will be post in raw form like the below json format. How can I Post this request to the server help me please.

    {
   "customer": {
      "email": "u144555@example.com",
      "firstname": "ok",
      "lastname": "Doe",
      "custom_attributes": [
          {
            "attribute_code": "phone_number1",
            "value": "12345"
          }
    ]
     },
   "password": "Admin@123"
    }