How to send a token from the SharedPreferences to MySQL with a session PHP script?

Question

I have web view app and I ask for help. I have the following scripts:  SharedPreference.java,  FirebaseInstanceIDService.java and  login.php, where is login.php hosted on the server.

I need to send the recorded token from SharedPreference to the MySQL database using the **login.php script that contains the session**.

When I delete the session from login.php, the token is record to the MySQL, when I return the session to the login.php the token is not recorded in the database.

Where am I wrong? Please Help.

**MainActivity.java**

    FirebaseMessaging.getInstance().subscribeToTopic("test");
    FirebaseInstanceId.getInstance().getToken();

**SharedPreference.java**

    import android.content.Context;
        import android.content.SharedPreferences;
    
        public class SharedPreference {
            private static final String SHARED_PREF_NAME = "FCMSharedPref";
            private static final String TAG_TOKEN = "tagtoken";
    
            private static SharedPreference mInstance;
            private static Context mCtx;
    
            private SharedPreference(Context context) {
                mCtx = context;
            }
            public static synchronized SharedPreference getInstance(Context context) {
                if (mInstance == null) {
                    mInstance = new SharedPreference(context);
                }
                return mInstance;
            }
            //this method will save the device token to shared preferences
            public boolean saveDeviceToken(String token){
                SharedPreferences sharedPreferences = mCtx.getSharedPreferences(SHARED_PREF_NAME, Context.MODE_PRIVATE);
                SharedPreferences.Editor editor = sharedPreferences.edit();
                editor.putString(TAG_TOKEN, token);
                editor.apply();
                return true;
            }
            //this method will fetch the device token from shared preferences
            public String getDeviceToken(){
                SharedPreferences sharedPreferences = mCtx.getSharedPreferences(SHARED_PREF_NAME, Context.MODE_PRIVATE);
                return  sharedPreferences.getString(TAG_TOKEN, null);
            }
    }

**FirebaseInstanceIDService.java**

    import android.util.Log;
    import com.google.firebase.iid.FirebaseInstanceId;
    import com.google.firebase.iid.FirebaseInstanceIdService;
    import java.io.IOException;
    import okhttp3.FormBody;
    import okhttp3.OkHttpClient;
    import okhttp3.Request;
    import okhttp3.RequestBody;
    
    
    public class FirebaseInstanceIDService extends FirebaseInstanceIdService {
    
        private static final String TAG = "FirebaseIIDService";
    
        @Override
        public void onTokenRefresh() {
    
            String token = FirebaseInstanceId.getInstance().getToken();
    
            registerToken(token);
        }
    
        private void registerToken(String token) {
    
            OkHttpClient client = new OkHttpClient();
            RequestBody body = new FormBody.Builder()
                    .add("Token",token)
                    .build();
    
            Request request = new Request.Builder()
                    .url("localhost/login.php”)
                    .post(body)
                    .build();
    
            try {
                client.newCall(request).execute();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    
        private void storeToken(String token) {
            //saving the token on shared preferences
            SharedPreference.getInstance(getApplicationContext()).saveDeviceToken(token);
        }
    }

**login.php**

    session_start();
    
    require_once(dirname(__FILE__) . "/users/su.inc.php");
    
        $UserK = new User();
    
        // Login from post data
        if( isset($_POST["username"]) )
        {
    
            $userId = $UserK->loginUser($_POST["username"], $_POST["password"]);
            if(!$userId) {
            $error = ‘Error username or password’;
            http_response_code(401);
        }
            else
            {
    
            if (isset($_REQUEST["Token"])) {
                require_once ("config.php");
    
                $_uv_Token=$_REQUEST["Token"];
    
                $conn = connect_db();
    
                $q="INSERT INTO user_push_notification (userId, Token) VALUES ({$userId}, '{$_uv_Token}') "
                    ." ON DUPLICATE KEY UPDATE Token = '$_uv_Token', userId={$userId};";
    
                mysqli_query($conn,$q) or die(mysqli_error($conn));
    
            }
    
    
            header("Location: menu.php");
            exit;
            }
    
    } // Validation end