You can control all activities in your own queue. The code is as follows:

public class ActivityUtils {

    private static List<Activity> activities = new ArrayList<>();
    
    public static void addActivity(Activity activity) {
        activities.add(activity);
    }

    /**
     * 关闭所有Activity
     */
    public static void finishAllActivity() {
        for (Activity activity : activities) {
            if (!activity.isFinishing()) {
                activity.finish();
            }
        }
    }
}

Add in the onCreate method in your BaseActivity:

ActivityUtils.addActivity(this);

Then call where you need

ActivityUtils.finishAllActivity();

Hope it helps you

Listen to the open activities in the application and kill all activities after clicking the button

application.registerActivityLifecycleCallbacks(new ActivityLifecycleCallbacks() {}

It seems that no one has answered, so I will post my own solution.
Still don’t know how to completely exit the APP, so I first clear the activity stack and then kill the process.

ActivityManager activityMgr= (ActivityManager)this.getSystemService(ACTIVITY_SERVICE);
 activityMgr.killBackgroundProcesses(getPackageName());
 android.os.Process.killProcess(android.os.Process.myPid()); 
System.exit(0);

Define an Activity queue, add each activity when it is created, and provide a static method to finish all activities in the queue