how can i call api without key in Volley ?

Question

hellow guys below is my code, i want to get data from api and populate in graph in android but when i call api its shows error please help me, how can i call , api which have no any key 

package com.example.myapplication;

import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;

import androidx.appcompat.app.AppCompatActivity;

import com.android.volley.Request;
import com.android.volley.RequestQueue;
import com.android.volley.Response;
import com.android.volley.VolleyError;
import com.android.volley.toolbox.JsonArrayRequest;
import com.android.volley.toolbox.JsonObjectRequest;
import com.android.volley.toolbox.Volley;

import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;

public class MainActivity extends AppCompatActivity {
    private TextView mTextViewResult;
    private RequestQueue mQueue;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        mTextViewResult = findViewById(R.id.text_view_result);
        Button buttonParse = findViewById(R.id.button_parse);

        mQueue = Volley.newRequestQueue(this);

        buttonParse.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                jsonParse();

            }
        });
    }

    private void jsonParse() {

        String url = "http://marjanjewellers.co/bilal/api.php";

        JsonObjectRequest request = new JsonObjectRequest(Request.Method.GET, url, null,
                new Response.Listener<JSONObject>() {
                    @Override
                    public void onResponse(JSONObject response) {
                        try {


                            JSONArray jsonArray = response.getJSONArray("0"); //here what i do

                            for (int i = 0; i < jsonArray.length(); i++) {
                                JSONObject employee = jsonArray.getJSONObject(i);

                                //String firstName = employee.getString("firstname");
                                //int age = employee.getInt("age");
                               // String mail = employee.getString("mail");

                              //  mTextViewResult.append(firstName + ", " + String.valueOf(age) + ", " + mail + "\n\n");
                            }
                        } catch (JSONException e) {
                            e.printStackTrace();
                        }
                    }
                }, new Response.ErrorListener() {
            @Override
            public void onErrorResponse(VolleyError error) {
                error.printStackTrace();
            }
        });

        mQueue.add(request);
    }

}

 and api response is like this 

 

[{"id":"1","altitude":"95.5","airpressure":"98.45","temperature":"45.89","pulserate":"85"}]