>>289354613

Okay, found the solution.
Put the APK on the Quest and use the app to install it:
https://www.apkmirror.com/apk/mobile-manager/apk-installer/apk-installer-8-6-2-release/apk-installer-8-6-2-android-apk-download/download/
Still sucks that SideQuest got $oy'd, though.