This situation has been something that's reoccured on two of my laptops that I have used Discord Screensharing on; basically whenever I stream the games I download from Itch.Io on Discord, I've been told that the audio for the games isn't audible.  This is only applicable to games from Itch.io, though! The audio from any other application like Chrome and games I download from Steam or any other website works fine from what users who have watched me said. 
I'm aware that this likely isn't something that can necessarily be fixed on my end, I don't believe. But I'm just wondering is this something that is applicable to anyone else? Additionally, can there be a way to fix this? I have a MacBook Pro, thought the laptop I had previously was a Microsoft Laptop, if that's useful in order to fix this. Very sorry if this is a rare situation! I'd just happened to catch onto this. 

Itch does not have a standard for audio or how to program the game. It's just a store.

Every game you download controls the audio differently depending on how it was programmed and itch.io has no control over this.

The problem must be on your side.

If you are using the itch.io app, try downloading the game from the web and running whitout the itch app. Maybe the problem is that discord is capturing the audio from the itch.io app and not from the game being launched from the itch.io app .