How to make a dark mode setting

I am new to android development and I am looking to make a dark mode setting in my application. For this I created a "preferences.xml" file which is displayed using a "SettingsActivity.java" file and a "SettingsFragment.java" file. I looked for a lot of solutions on the internet but none worked. Does anyone have a tutorial, example or solution? Thanks

preferences.xml

<?xml version="1.0" encoding="utf-8"?>
<PreferenceScreen xmlns:android="http://schemas.android.com/apk/res/android">

    <ListPreference
            android:key="@string/key_app_theme"
            android:title="@string/app_theme"
            android:summary=""
            android:icon="@drawable/ic_app_theme"
            android:entries="@array/pref_app_theme_entries"
            android:entryValues="@array/pref_app_theme_values"
            android:dialogTitle="@string/app_theme"
            android:defaultValue="1"/>

</PreferenceScreen>

arrays.xml

<?xml version="1.0" encoding="utf-8"?>
<resources>
    
    <string-array name="pref_app_theme_entries">
        <item>@string/system</item>
        <item>@string/battery_saver</item>
        <item>@string/light</item>
        <item>@string/dark</item>
    </string-array>
    <string-array name="pref_app_theme_values">
        <item>1</item>
        <item>2</item>
        <item>3</item>
        <item>4</item>
    </string-array>
    
</resources>

activity_settings.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:id="@+id/activity_settings"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="@color/colorPrimary"
    tools:context=".SettingsActivity">

    <androidx.appcompat.widget.Toolbar
        android:id="@+id/activity_settings_toolbar"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:elevation="4dp"
        android:background="@color/colorPrimaryDark"
        app:title="@string/settings"
        app:titleTextColor="@color/colorAccent" />

    <FrameLayout
        android:id="@+id/activity_settings_fragment_container"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_below="@id/activity_settings_toolbar" />

</RelativeLayout>

SettingsActivity.java

public class SettingsActivity extends AppCompatActivity {

    private static Preference settings;

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

        if (findViewById(R.id.activity_settings_fragment_container) !=null) {
            if (savedInstanceState != null)
                return;

            getFragmentManager().beginTransaction().add(R.id.activity_settings_fragment_container, new SettingsFragment()).commit();
        }

        Toolbar toolbar = findViewById(R.id.activity_settings_toolbar);
        toolbar.setTitleTextAppearance(this, R.style.KaushanScriptRegular);
        toolbar.setNavigationIcon(R.drawable.ic_back);
        toolbar.setNavigationOnClickListener(view -> {
            Intent intent = new Intent(SettingsActivity.this, MainActivity.class);
            startActivity(intent);
            overridePendingTransition(R.anim.swipe_right_enter, R.anim.swipe_right_exit);
        });
    }
}

SettingsFragment.java

public class SettingsFragment extends PreferenceFragment {

    @Override
    public void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        addPreferencesFromResource(R.xml.preferences);
}