CameraViewWrapper

App.js

// Just an excerpt of the relevant part here

        <Button
            title="Click to invoke your native module!"
            color="#841584"
            onPress={() => {CameraViewWrapper.testEvent()}}
          />

CameraViewWrapper.java

package com.shadercam;
import com.facebook.react.bridge.NativeModule;
import com.facebook.react.bridge.ReactApplicationContext;
import com.facebook.react.bridge.ReactContext;
import com.facebook.react.bridge.ReactContextBaseJavaModule;
import com.facebook.react.bridge.ReactMethod;
import java.util.Map;
import java.util.HashMap;
import android.util.Log;

public class CameraViewWrapper extends ReactContextBaseJavaModule {
    CameraViewWrapper(ReactApplicationContext context) {
        super(context);
    }

    @Override
    public String getName() {
        return "CameraViewWrapper";
    }
    
    @ReactMethod
    public void testEvent() {
        Log.d("ReactNative","Notify App");
    }
}

CameraViewWrapperPackage.java

package com.shadercam;
import com.facebook.react.ReactPackage;
import com.facebook.react.bridge.NativeModule;
import com.facebook.react.bridge.ReactApplicationContext;
import com.facebook.react.uimanager.ViewManager;

import java.util.ArrayList;
import java.util.Collections;
import java.util.List;

public class CameraViewWrapperPackage implements ReactPackage {

    @Override
    public List<ViewManager> createViewManagers(ReactApplicationContext reactContext) {
        return Collections.emptyList();
    }

    @Override
    public List<NativeModule> createNativeModules(
            ReactApplicationContext reactContext) {
        List<NativeModule> modules = new ArrayList<>();

        modules.add(new CameraViewWrapper(reactContext));

        return modules;
    }

}

MainApplication.java

// Just an excerpt of the changed part here

        @Override
        protected List<ReactPackage> getPackages() {
          @SuppressWarnings("UnnecessaryLocalVariable")
          List<ReactPackage> packages = new PackageList(this).getPackages();
          // Packages that cannot be autolinked yet can be added manually here, for example:
           packages.add(new CameraViewWrapperPackage());
          return packages;
        }