import androidx.appcompat.app.AppCompatActivity; import androidx.appcompat.widget.Toolbar; public class MainActivity extends AppCompatActivity { @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); Toolbar toolbar = findViewById(R.id.toolbar); setSupportActionBar(toolbar); } } dependencies { implementation 'androidx.appcompat:appcompat:1.3.0' }