I don’t know what to say. Internally, Krabby uses KeyboardEvent.code with a layer (US by default) for the display.
https://developer.mozilla.org/en-US/docs/Web/API/KeyboardEve...
https://developer.mozilla.org/en-US/docs/Web/API/KeyboardEve...
(Since I can't edit my previous post anymore: ignore the mention of the escape key, alt+esc is actually the only alt combo that works.)