StarryDrive is distributed as a Roblox Studio plugin file and is installed manually.
Open your local Roblox Studio plugins folder.
Windows: %localappdata%\Roblox\Plugins macOS: ~/Documents/Roblox/Plugins
Copy the downloaded StarryDrive plugin file into the Plugins folder.
Close and reopen Roblox Studio. StarryDrive should now appear in the Plugins tab and is ready to use.
Plugins folder, then restart Roblox Studio. If you're still having issues, see the Troubleshooting page.