Interested in playing Minecraft in VR. My friend decided to use the mod Vivecraft and the modloader Fabric.
Apparently, even though the official Fabric installation instructions (https://docs.fabricmc.net/players/installing-fabric) never explicitly says this, you do in fact want the official Minecraft launcher installed first before installing Fabric.
After installation, I found that the installer window could not be closed despite it saying that installation had been completed. This was because it spawned a popup on my other monitor informing me that installation had been completed and that needed to be closed first.