Unity editor tools for VRChat creators — Kawaii Studio.
One click. VCC opens, adds the listing, and every future release shows up as an update automatically.
Add to VRChat Creator Companion
Prefer to add it by hand? In VCC go to Settings → Packages → Add Repository and paste:
https://kawaiistudio.github.io/KSUnityTools/index.json
Double-click it with your Unity project open. Everything installs under Assets/Kawaii Studio; the VRChat tools switch on by themselves when the SDK is present.