Simple ill take you through a step by step guide on how to install apps
PC Scroll down for Stand-alone
You need to install Advanced side quest SideQuest (sidequestvr.com)
you need to get an app preferably from us
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Press this button
Select the app
Now your done
QUEST
Download Mobile VR Station
Download an app
Open Mobile VR Station
Press "Local Files"
"All Folders"
"Android"
"data"
"Scoped Storage Actions"
Press "step 1 request access"
Under data in top corner press "Quest 2" or "Stand alone quest"
Click "download" or "downloads"
You should see your downloaded folder "(App Name).apk"
Press the Fullscreen option
A window should pop up saying "install" or "allow" just press continue (If it does not pop up keep trying)
Quit Mobile VR Station
Press 9-dots (apps button)
Go to unknown sources
Your app should be there
Click it to run it