Hey @celest vessel what country are you from? You can try and press the ? on the bottom right corner and change the keyboard layout because it comes as US keyboard by default.
Another shortcut that has been working for me has been CTRL + Alt + ⬇️⬆️
#How to move layers one step up?
thick cape
vagrant cave
I think Bruno's guess is right about your keyboard being different than standard English keyboard. Mine is different as well, that symbol is supposed to be to the right of letter P, and I've had similar problems with shortcuts. But a recent post about upcoming updates to Figma actually mentions a possible fix for this, number 3. https://twitter.com/mwichary/status/1592190045460791299