Please note that this method is still in beta, and might have unexpected or undocumented results.
1. Install SteamVR
Download and install from the Steam page
2. Install Varjo Base
3. Install Epic Launcher
6. Open your project
Open your project using UE.
7. Enable OpenXR plugin
8. Disable SteamVR plugin
9. Run your project
10. Check the Performance and Visual Quality guidance
Tune the project with the guidance from Performance and Visual Quality page.