Power Apps- Enable Modern Controls

Step 1:

From the Power Apps studio, click on ‘Settings’

Step 2:

1. Click on ‘Updates’ tab
2. Turn on ‘Modern controls and themes’

Conclusion:

The modern controls will now be the default choices when you insert controls.

Try to click on Insert, and search for a button, you will notice that the default button is now modern and the classic button can be found below.