App crashing after clicking login button in Android studio

So, this app is for my class library, but whenever I click login in the 1st activity after putting in my details, the app crashes. Please look at this issue.

My 1st Main activity code:

package com.cls2r.library;

import androidx.appcompat.app.AppCompatActivity;

import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;

public class MainActivity extends AppCompatActivity {
    EditText login_text, password_text;
    Button login;

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

        login_text = (EditText) findViewById(R.id.login);
        password_text = (EditText) findViewById(R.id.password);
        login = (Button) findViewById(R.id.button_login);

        login.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {

                String username = login_text.getText().toString();
                String password = password_text.getText().toString();

                if(username.equals("admin") && (password.equals("123456")))
                {
                    Toast.makeText(MainActivity.this, "Welcome Soham", Toast.LENGTH_SHORT).show();
                    Intent intent=new Intent(getApplicationContext(),MainActivit2y.class);
                    startActivity(intent);
                }else
                {
                    Toast.makeText(MainActivity.this, "Welcome Guest", Toast.LENGTH_SHORT).show();
                    Intent intent=new Intent(getApplicationContext(),MainActivit2y.class);
                    startActivity(intent);
                }
            }
        });


        }
    }

Other MainActivity code:

package com.cls2r.library;

import androidx.annotation.NonNull;
import androidx.appcompat.app.AppCompatActivity;

import android.graphics.Bitmap;
import android.os.Bundle;
import android.webkit.WebSettings;
import android.webkit.WebView;
import android.webkit.WebViewClient;

import com.google.android.gms.ads.AdRequest;
import com.google.android.gms.ads.AdView;
import com.google.android.gms.ads.MobileAds;
import com.google.android.gms.ads.initialization.InitializationStatus;
import com.google.android.gms.ads.initialization.OnInitializationCompleteListener;

public class MainActivit2y extends AppCompatActivity {

    private AdView mAdView;
    private WebView webView;


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main1);

        MobileAds.initialize(this, new OnInitializationCompleteListener() {
            @Override
            public void onInitializationComplete(@NonNull InitializationStatus initializationStatus) {

            }
        });
        mAdView = findViewById(R.id.adView);
        AdRequest adRequest= new AdRequest.Builder().build();
        mAdView.loadAd(adRequest);

        webView=(WebView) findViewById(R.id.web_view);
        webView.setWebViewClient(new WebViewClient());
        webView.loadUrl("https://sites.google.com/view/cls2rlibraryybis/home");
        WebSettings webSettings=webView.getSettings();
        webSettings.setJavaScriptEnabled(true);
    }
    public class mywebClient extends WebViewClient {
        @Override
        public void onPageStarted(WebView view, String url, Bitmap favicon) {
            super.onPageStarted(view,url,favicon);
        }
        @Override
        public boolean shouldOverrideUrlLoading(WebView view, String url) {
            view.loadUrl(url);
            return true;
        }
    }
    @Override
    public void onBackPressed() {
        if (webView.canGoBack()) {
            webView.goBack();
        } else {
            super.onBackPressed();
        }
    }
}

Please try to resolve this issue. I built the app to a signed APK file and deployed it on my device for testing, and the app kept on crashing after I clicked the login button. I thought it would open the next activity, but no. Please check for my mistake...

There are many factors causing crash of an activity. However, here are some general factors.

• Your activity is not registered in the manifest
• If you run in android 12, the activity in the manifest should have android:exported attribute.
• If you use hilt and hilt view model, you might forget to add @AndroidEntryPoint.
• If your activity extends AppCompatActivity, the activity might not apply AppCompat theme.

To inspect more accurately, please provide the error message.