You may be able to reuse the app from the "Fill Out A Form" exercise. (Set up an app with 3 Text Input boxes, and a Label above each box. Put a Label at the top of the app and a Button at the bottom.)
In this app, it is only necessary to fill out one of the 3 boxes before clicking the Submit button. When the user clicks the button, if all of the boxes are empty, the app displays the message "Please fill out at least one field" and a sound plays. Once one or more boxes are filled out, the app displays the message, "Information submitted" and a different sound plays. Changing the color of text and of backgrounds is optional.
The video shows what a completed app should do.