Bruh, there's a web version specifically for ChromeOS. OP could also boot Lakka off of a USB drive or SD card. ChromeOS also isn't Windows. Don't come in talking shit when you have no idea what's going on.
I know there was a web version, but most chrome books are based off of gmail accounts in the district database. Meaning that most chrome extensions are banned for the locked school account.
Also It’s my belief that Lakka isint a portable program and can’t be launched without being installed (I might be wrong).
Also... I know Chrome OS isn't windows. Sorry but I don’t get the roast here.
EDIT: Fuck okay you win, I just realized that Lakka can be installed directly inside of the USB on a separate computer and then be bought to the school chromebook.
So I was wrong in that aspect.