How can I have an app play audio sounds when it is run on an iPhone? Audio only works when I run the app in Simulator

Relatively new to Swift, but I created a music trivia game and another simple game, both of which incorporate audio. The audio capabilities work perfectly fine within Simulator but don't work when I port the apps to my phone. Any help would be greatly appreciated, thanks.

What is the audio source?

How can I have an app play audio sounds when it is run on an iPhone? Audio only works when I run the app in Simulator
 
 
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