Hey Hillbillys!
Sorry you’re having problems. I would say it’s easiest to use your PC to install the app rather than do it by Android.
First of all, the Quest needs to be in developer mode (if it’s not, you can google how to set up developer mode on Quest)
Download the PTHS .apk file (you should have a link in the email from when you purchased the game) to your PC.
Then go to the SideQuest webpage on your PC and download the SideQuest app for Windows.
Once you have SideQuest installed on your PC, connect your Quest up to the PC via USB and choose the ‘install apk’ option in the SideQuest tools, select the PTHS .apk file and it will install it to your Quest.
Then you can run the app from the ‘Unknown Sources’ menu in the Quest.
I hope this helps!