how do you update roblox?

one catch on pc - if you got it from the microsoft store rather than the website, it updates through the store's library page, not when you launch. that version can sit outdated for ages and the game just refuses to join servers.

on pc it patches itself the moment you launch it, so if yours isn't updating then something is blocking it and reinstalling is quicker than working out what. phone and tablet it's just the app store like anything else. xbox goes through the console's own update list, you can't force that one from inside the app.