First of all get Mobile VR Station from applab. Allow it to manage files and click on local files/all folders/android/data. And you will have an error, click on scoped storage actions and then step 1. There should be text around the top saying anything listed here: "Standalone HMD", "Quest 2", and "Quest 3". Click on it and go into download. Press the arrows pointing away from a center on the apk you want to sideload! The popup may be invisible so just click around the right side of the screen you get and check your unknown sources until it works!