When you click play, Firefox should ask for permission to open the Roblox Launcher.
In Firefox, go to the Roblox site and trigger a fresh download. roblox download firefox
A pop-up will appear prompting you to download the Roblox Player. Save the .exe (Windows) or .dmg (Mac) file. Open the downloaded file to install the client. Return to Firefox and click Play again to launch the game. Optimizing Firefox for Roblox Performance When you click play, Firefox should ask for
Reinstall to sync the browser hook with the latest client version. Plugin Support Note Save the
Firefox does not "run" Roblox directly inside a tab like a flash game. Instead, the browser acts as a portal that triggers the Roblox Player application installed on your computer. Head to the official Roblox website using Firefox. Log in to your account or create a new one. Select any game and click the green Play button.