Install Sidequest and activate Developer Mode. If you're not in developer mode follow these instructions. https://learn.adafruit.com/sideloading-on-oculus-quest/enable-developer-mode
If You have sidequest and developer mode on, open sidequest
Locate the Custom APK Option and then select the downloaded APK from releases.
On your headset locate "Unknown Sources" and then you'll see the codename "Mario_Sightsee" which is this project.