Upload a pack
Pick a Java Edition resource pack (.zip, up to 60 MB). Its block textures are fitted to the VRChat map; blocks it doesn't change keep the normal look.
Use it in VRChat
The instance master pastes the link into the Texture pack box by the live view screen and presses Enter. Everyone in the instance then sees the pack. Clearing the box goes back to normal. VRChat needs Allow Untrusted URLs on.