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, you want to guarantee that the user has filled out all 3 boxes. When the user clicks the button, if any of the boxes is empty, the app displays the message "Please fill out all fields" and a sound plays. Once all the 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.
Suggestion: you may want to use a boolean variable to keep track of whether or not all 3 boxes have something in them. You could begin by setting the boolean to 'true.' You could then use an IF statement for each box to see if it's empty. If it's empty, you could set the boolean to 'false.' After all 3 IF statements, depending on the value of the boolean, display a message and play a sound.
The video shows what a completed app should do.