If it doesn't work check the addon folder in Appdata/Roaming/Blender Foundation/2.80/scripts/addons is called blender-rigui (latest release) Addon is very much WIP ...

Roblox FPS Booster is a performance tool designed to improve frame rates and reduce lag during gameplay on low- and mid-tier Windows PCs. Maximize performance and eliminate lag in Roblox with this ...