Can I open my application on top of the rest?

Question

Android

I need an event, for example, a timer to open the application on top of the rest. They suggested the following code:

Intent intent = new Intent(context, MainActivity.class);
intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
context.startActivity(intent);

But it doesn't work. I am not familiar with such intricacies of android, what is the best and easiest way to do it?