no apps can perform this action android studio

Question

Im new to this area, I have a mission, I have build up an application that register some data that I have insert. lets call this app "A", now i copy the same app and called it "B". In app "A" and "B" in the manifest file I write this:

<activity
            android:name=".Register"
            android:exported="false">
            <intent-filter>
                <action android:name="com.action.ex3.register" />
                <category android:name="android.intent.category.DEFAULT" />
            </intent-filter>
        </activity>

Now in app "C" I want to use what app "A" or "B" doing, in order to to that in the app "C" I write this:

public void registerBtnClicked(View view) {
        Intent intent = new Intent(); //implicit activity.
        intent.setAction("com.action.ex3.register");
        startActivityForResult(intent, REGISTER_ID);
    }

what I expected that will happen it that when I press in my app "C" on the regiser button a pop out with a "chooser dialog" with option to choose "A" or "B", but instead of that I got "chooser dialog" with "no apps can perform this action android studio"

what im doing wrong? here a picture of the problem

App C "no apps can perform this action android studio"

Im using pixel emulator in android studio IDE.

Answer 1

Your activities are not exported. They cannot be accessed from other apps. Change android:exported to be true if you want other apps accessing your activities.