In what way do I have to export my game so that when there is an error or something I can update it on that page (PC)
I did not understand the end of your sentence, sorry.
I want to export my game to a computer but I want to know how my game is updated
That depends on your distribution method. If you straight up distribute the exe file, people will have to keep getting updated on the platform you uploaded it and download and reinstall the game for each release. You could also decide to go through a launcher (making your own, Steam, Gamejolt, Itch (the last two also permits the classical way)), or you could code an updater or use an existing one (on manual build with electron builder there is a such option I think).