Android Studio Activity doesn't start

When starting my activity there is always an error message and the app does not open.

Error:

2022-05-11 23:18:12.470 17222-17222/com.example.myapplication E/AndroidRuntime: FATAL EXCEPTION: main
    Process: com.example.myapplication, PID: 17222
    java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{com.example.myapplication/com.example.feuerwerkzndanlage.Biometric_Authentication}: java.lang.NullPointerException: Attempt to invoke virtual method 'android.content.Context android.content.Context.getApplicationContext()' on a null object reference
        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3455)
        at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3699)
        at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:85)
        at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:135)
        at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:95)
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2135)
        at android.os.Handler.dispatchMessage(Handler.java:106)
        at android.os.Looper.loop(Looper.java:236)
        at android.app.ActivityThread.main(ActivityThread.java:8056)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:656)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:967)
     Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'android.content.Context android.content.Context.getApplicationContext()' on a null object reference
        at android.content.ContextWrapper.getApplicationContext(ContextWrapper.java:133)
        at com.example.feuerwerkzndanlage.Biometric_Authentication.<init>(Biometric_Authentication.java:23)
        at java.lang.Class.newInstance(Native Method)
        at android.app.AppComponentFactory.instantiateActivity(AppComponentFactory.java:95)
        at androidx.core.app.CoreComponentFactory.instantiateActivity(CoreComponentFactory.java:45)
        at android.app.Instrumentation.newActivity(Instrumentation.java:1254)
        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3443)
        at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3699) 
        at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:85) 
        at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:135) 
        at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:95) 
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2135) 
        at android.os.Handler.dispatchMessage(Handler.java:106) 
        at android.os.Looper.loop(Looper.java:236) 
        at android.app.ActivityThread.main(ActivityThread.java:8056) 
        at java.lang.reflect.Method.invoke(Native Method) 
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:656) 
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:967) 

Activity:

package com.example.feuerwerkzndanlage;

import android.annotation.SuppressLint;
import android.content.Context;
import android.os.Bundle;
import android.widget.Button;
import android.widget.TextView;
import android.widget.Toast;

import androidx.annotation.NonNull;
import androidx.appcompat.app.AppCompatActivity;
import androidx.biometric.BiometricPrompt;
import androidx.core.content.ContextCompat;

import java.util.concurrent.Executor;

public class Biometric_Authentication extends AppCompatActivity {

    private TextView authStatusTv;
    private BiometricPrompt biometricPrompt;
    private BiometricPrompt.PromptInfo promptInfo;

    Context context = getApplicationContext();
    CharSequence error_txt = "Indentifizierung Fehlgeschlagen: ";
    CharSequence suceed_txt = "Indentifizierung Erfolgreich";
    CharSequence failed_txt = "Indentifizierung Fehlgeschlagen";
    int duration = Toast.LENGTH_SHORT;


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

        authStatusTv = findViewById(R.id.authStatusTv);
        Button btn_auth = findViewById(R.id.btn_auth);

        Executor executor = ContextCompat.getMainExecutor(this);
        biometricPrompt = new BiometricPrompt(Biometric_Authentication.this, executor, new BiometricPrompt.AuthenticationCallback() {
            @SuppressLint("SetTextI18n")
            @Override
            public void onAuthenticationError(int errorCode, @NonNull CharSequence errString) {
                super.onAuthenticationError(errorCode, errString);
                authStatusTv.setText("Indentifizierung Fehlgeschlagen: " + errString);
                Toast.makeText(context, error_txt, duration).show();
            }

            @SuppressLint("SetTextI18n")
            @Override
            public void onAuthenticationSucceeded(@NonNull BiometricPrompt.AuthenticationResult result) {
                super.onAuthenticationSucceeded(result);
                authStatusTv.setText("Indentifizierung Erfolgreich");
                Toast.makeText(context, suceed_txt, duration).show();
            }

            @SuppressLint("SetTextI18n")
            @Override
            public void onAuthenticationFailed() {
                super.onAuthenticationFailed();
                authStatusTv.setText("Indentifizierung Fehlgeschlagen");
                Toast.makeText(context, failed_txt, duration).show();
            }
        });

        promptInfo = new BiometricPrompt.PromptInfo.Builder()
                .setTitle("Biometrische Indentifizierung")
                .setSubtitle("Login")
                .setNegativeButtonText("Benutzer Passwort")
                .build();

        btn_auth.setOnClickListener(view -> biometricPrompt.authenticate(promptInfo));

    }
}