Android app not displaying string in Yii 2 framework

[Prashant Sontale]

package com.example.anitaa.student;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;

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.StringRequest;
import com.android.volley.toolbox.Volley;

public class MainActivity extends AppCompatActivity {
    TextView text;
    Button b1;
   
String url1="http://192.168.1.3/student/web/index.php?r=message/display";

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        text=(TextView) findViewById(R.id.text_content);
        b1=(Button) findViewById(R.id.btn5);
        b1.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                final RequestQueue requestQueue1= Volley.newRequestQueue(MainActivity.this);
                StringRequest stringRequest1=new StringRequest(Request.Method.POST, url1, new Response.Listener<String>() {
                    @Override
                    public void onResponse(String response) {
                           text.setText(response);
                           requestQueue1.stop();
                    }
                }, new Response.ErrorListener() {
                    @Override
                    public void onErrorResponse(VolleyError error) {
                        text.setText("Error");
                        error.printStackTrace();
                        requestQueue1.stop();
                    }
                });
                requestQueue1.add(stringRequest1);
            }
        });
    }
}

Hi I am using PHP Yii framework. I have below code but it does not display the string value