Re: how do I use firefox for candy crush cheats???
Are you talking about the Leethax Firefox extension ?
If yes, once you've installed the plugin all the cheats will be activated automatically (Infinite lives and boosts,All unlocked charms are bought)- if it does not works anymore, probably the cheat has been patched or you are experiencing issues with the extension.
But you should take care though with Add-ons that are not in the marketplace. Also, cheating is sort of bad, but it's up to you anyway.