How to catch the F key in FireFox?

Question

JavaScript

With the last of my strength, I'm trying to make cross-platform sites that work not only in Chrome. Faced with the fact that I can not find a way to catch the F key press event in FireFox. Please tell me how to do this:
The following code does not catch pressing the F-buttons.

document.addEventListener('keypress', (event) => 
{
   var key=event.key;
   console.log("key: ", key)
})

Answer 1

which code is not working?
esc is 27
keycode.info