If you are trying to install Polar on quest 3 follow these instructions
1. First get mobile vr station or open it
2. Go to Local files
3. All folders
4. Go to android
5. Click on OBB
6. Click on Scoped Storage Actions
7. Click Step 1: Request Access
8. In Files click Quest 3 on top left screen
9. Scroll down to Downloads
10. Click the load button and click download
11. Enjoy