error appcompat

[behnamk]

I wrote similar to the sample code. But when I run, I get this error.

java.lang.RuntimeException: ...com.zhihu.matisse.ui.MatisseActivity}: java.lang.NullPointerException: Attempt to invoke virtual method 'void androidx.appcompat.app.ActionBar.setDisplayShowTitleEnabled(boolean)' on a null object reference

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

    button = findViewById(R.id.btn);
    button.setOnClickListener(v -> {
        Matisse.from(this)
                .choose(MimeType.ofAll(), false)
                .countable(true)
                .capture(true)
                .captureStrategy(
                        new CaptureStrategy(true, "com.zhihu.matisse.sample.fileprovider", "test"))
                .maxSelectable(9)
                .addFilter(new GifSizeFilter(320, 320, 5 * Filter.K * Filter.K))
                .gridExpectedSize(
                        getResources().getDimensionPixelSize(R.dimen.grid_expected_size))
                .restrictOrientation(ActivityInfo.SCREEN_ORIENTATION_PORTRAIT)
                .thumbnailScale(0.85f)
                .imageEngine(new GlideEngine())
                .autoHideToolbarOnSingleTap(true)
                .setOnSelectedListener((uriList, pathList) -> {
                    Log.e("onSelected", "onSelected: pathList=" + pathList);
                })
                .showSingleMediaType(true)
                .originalEnable(true)
                .maxOriginalSize(10)
                .autoHideToolbarOnSingleTap(true)
                .setOnCheckedListener(new OnCheckedListener() {
                    @Override
                    public void onCheck(boolean isChecked) {
                        Log.e("isChecked", "onCheck: isChecked=" + isChecked);
                    }
                })
                .forResult(REQUEST_CODE_CHOOSE);

    });

---

<style name="AppTheme" parent="Theme.AppCompat.Light.NoActionBar">
    <!-- Customize your theme here. -->
    <item name="colorPrimary">#0F0A05</item>
    <item name="colorPrimaryDark">#98000000</item>
    <item name="colorAccent">#DF1045</item>
    <item name="android:windowAnimationStyle">@style/Animation.Design.BottomSheetDialog</item>
</style>

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