Anyway to use debugger after exporting?

^^^^^

No, you can't use the debugger after exporting.

Why would you want to? Debugging is part of the development process, but you generally don't want debugging features enabled in your exported build. Otherwise all of your players would be able to access it and see all the inner workings of your game.

I'm curious what kind of situation you could be in that specifically requires use of the debugger on the exported game?

sure press f12

Add "Browser Log" to key events which you want to debug, for example outputting variable values etc.

Then press F12 when you run the game and check messages in the console log.