Cannot resolve symbol 'onCompleteListener' - android-studio

Question

I followed this tutorial https://morioh.com/p/10dc2d87bb2f but despite doing everything the same i get the following error:
error: cannot find symbol
mAuth.signInWithCredential(authCredential).addOnCompleteListener( MainActivity.his,new onCompleteListener() {
^
symbol: variable his
location: class MainActivity
I tried changing the cersions of play-services and firebase-auth/core but nothing changed.
My MainActivity.java:
package com.imoroney.easylearn;
import androidx.annotation.NonNull;
import androidx.annotation.Nullable;
import androidx.appcompat.app.AppCompatActivity;
import android.content.Intent;
import android.net.Uri;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;
import com.google.android.gms.auth.api.signin.GoogleSignIn;
import com.google.android.gms.auth.api.signin.GoogleSignInAccount;
import com.google.android.gms.auth.api.signin.GoogleSignInClient;
import com.google.android.gms.auth.api.signin.GoogleSignInOptions;
import com.google.android.gms.common.SignInButton;
import com.google.android.gms.common.api.ApiException;
import com.google.android.gms.tasks.Task;
import com.google.firebase.auth.AuthCredential;
import com.google.firebase.auth.AuthResult;
import com.google.firebase.auth.FirebaseAuth;
import com.google.firebase.auth.FirebaseUser;
import com.google.firebase.auth.GoogleAuthProvider;
import com.google.android.gms.tasks.OnCompleteListener;
public class MainActivity extends AppCompatActivity {
private SignInButton signInButton;
private GoogleSignInClient mGoodleSignInClient;
private String TAG = "MainActivity";
private FirebaseAuth mAuth;
private Button btnSignOut;
private int RC_SIGN_IN = 1;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
signInButton = findViewById(R.id.sign_in_button);
mAuth = FirebaseAuth.getInstance();
btnSignOut = findViewById(R.id.sign_out_button);
GoogleSignInOptions gso = new GoogleSignInOptions.Builder(GoogleSignInOptions.DEFAULT_SIGN_IN).requestIdToken(getString(R.string.default_web_client_id)).requestEmail().build();
mGoodleSignInClient = GoogleSignIn.getClient(this,gso);
signInButton.setOnClickListener(new View.OnClickListener(){
#Override
public void onClick(View view){
signIn();
}
});
btnSignOut.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
mGoodleSignInClient.signOut();
Toast.makeText(MainActivity.this,"You Are Signed Out", Toast.LENGTH_SHORT).show();
btnSignOut.setVisibility(View.INVISIBLE);
}
});
}
private void signIn(){
Intent signInIntent = mGoodleSignInClient.getSignInIntent();
startActivityForResult(signInIntent,RC_SIGN_IN);
}
#Override
protected void onActivityResult(int requestCode, int resultCode, #Nullable Intent data) {
super.onActivityResult(requestCode, resultCode, data);
if(requestCode == RC_SIGN_IN) {
Task<GoogleSignInAccount> task = GoogleSignIn.getSignedInAccountFromIntent(data);
handleSignInResult(task);
}
}
private void handleSignInResult(Task<GoogleSignInAccount> completedTask){
try {
GoogleSignInAccount acc = completedTask.getResult(ApiException.class);
Toast.makeText(MainActivity.this,"Signed In Successfully", Toast.LENGTH_SHORT).show();
FirebaseGoogleAuth(acc);
}
catch (ApiException e){
Toast.makeText(MainActivity.this,"Sign In Failed", Toast.LENGTH_SHORT).show();
FirebaseGoogleAuth(null);
}
}
private void FirebaseGoogleAuth(GoogleSignInAccount acct){
AuthCredential authCredential = GoogleAuthProvider.getCredential(acct.getIdToken(),null);
mAuth.signInWithCredential(authCredential).addOnCompleteListener( MainActivity.his,new onCompleteListener<AuthResult>() {
#Override
public void onComplete(#NonNull Task<AuthResult> task){
if(task.isSuccessful()){
Toast.makeText(MainActivity.this,"Successful", Toast.LENGTH_SHORT).show();
FirebaseUser user = mAuth.getCurrentUser();
updateUI(user);
}
else{
Toast.makeText(MainActivity.this,"Failed", Toast.LENGTH_SHORT).show();
updateUI(null);
}
}
});
}
private void updateUI(FirebaseUser fUser){
btnSignOut.setVisibility(View.VISIBLE);
GoogleSignInAccount account = GoogleSignIn.getLastSignedInAccount(getApplicationContext());
if(account != null){
String personName = account.getDisplayName();
String personGivenName = account.getGivenName();
String personFamilyName = account.getFamilyName();
String personEmail = account.getEmail();
String personId = account.getId();
Uri personPhoto = account.getPhotoUrl();
Toast.makeText(MainActivity.this, personName + personEmail, Toast.LENGTH_SHORT).show();
}
}
}
My build gradle:
apply plugin: 'com.android.application'
apply plugin: 'com.google.gms.google-services'
android {
compileSdkVersion 29
buildToolsVersion "29.0.3"
defaultConfig {
applicationId "com.imoroney.easylearn"
minSdkVersion 16
targetSdkVersion 29
versionCode 1
versionName "1.0"
testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
}
buildTypes {
release {
minifyEnabled false
proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
}
}
}
dependencies {
implementation fileTree(dir: "libs", include: ["*.jar"])
implementation 'androidx.appcompat:appcompat:1.1.0'
implementation 'androidx.constraintlayout:constraintlayout:1.1.3'
implementation 'com.google.firebase:firebase-auth:19.3.2'
testImplementation 'junit:junit:4.12'
androidTestImplementation 'androidx.test.ext:junit:1.1.1'
androidTestImplementation 'androidx.test.espresso:espresso-core:3.2.0'
implementation 'com.google.firebase:firebase-core:17.5.0'
implementation 'com.google.android.gms:play-services-auth:18.1.0'
implementation 'com.google.firebase:firebase-messaging:20.2.4'
}