... Chromebook desktop
I don’t have any chromebook to test this, but Unity doesn’t support chromebooks.
I suggest that you play Backrooms on other supported devices (Windows, Linux or Mac) or try to emulate the Linux version of it in your chromebook:
https://support.google.com/chromebook/answer/9145439?hl=en
I have no idea that this will work or not, but see if you have a chromebook that has graphic hardware acceleration enabled for linux first before emulating.