This is the default Firefox Browser hotkeys any changes to this is up to the Addon or 3rd party software to support if there is issues to their changes.

https://support.mozilla.org/en-US/kb/keyboard-shortcuts-perform-firefox-tasks-quickly

The browser extension supports customizable hotkeys. The thing is when I try to type those keys in the firefox about:addons page, inside Manage Extension Shortcuts, I see this screen which I'm attaching to this post. The window does not allow me to type the backtick key or any other key that is not either a number or alphabet.

So I'm basically restricted to using Ctrl + <alphanum> and Ctrl + Alt + <alphanum> .

The extension supports Ctrl + backtick (`) but it appears that this is not enabled and I need to type the shortcut key in Firefox's Manage Extensions Shortcuts options page.

But it isn't allowing me to do that. You can see in my screenshot that I have mapped Ctrl + M and Ctrl + Q to these two shortcuts. But I would like to map something else, preferrably Ctrl + backtick. I even tried Ctrl + { and Ctrl + } but like I said the input box only accepts alphabets and numbers and no other keys.

You said extension that isn't a Firefox Hotkey default.

Yes, please see the title of my original post. This is about extension shortcut keys. I am trying to setup a shortcut key for my extension. I am not trying to reset Firefox's default hotkeys.

Here's a list of allowed keys: https://searchfox.org/mozilla-central/source/toolkit/mozapps/extensions/content/shortcuts.js#84

   "0" - "9",
   "A" - "Z",
   F1 - F19,
   "MediaNextTrack", "MediaPlayPause", "MediaPrevTrack", "MediaStop",
   "Up",  "Down", "Left",  "Right",
   "Comma", "Period",
   "Space",
   "Home", "End",
   "PageUp", "PageDown",
   "Insert",  "Delete"

You can't use anything else without recompiling Firefox.

Thanks @TyDraniu! i'll try these and report back. any more keys besides the alphabets would help, i could work with home and end or comma and period. any of those should work.

Here's a list of allowed keys: https://searchfox.org/mozilla-central/source/toolkit/mozapps/extensions/content/shortcuts.js#84 "0" - "9", "A" - "Z", F1 - F19, "MediaNextTrack", "MediaPlayPause", "MediaPrevTrack", "MediaStop", "Up", "Down", "Left", "Right", "Comma", "Period", "Space", "Home", "End", "PageUp", "PageDown", "Insert", "Delete" You can't use anything else without recompiling Firefox.

these keys all seem to work. some seem bound to other functions, either Firefox defaults or perhaps some extension. but this really helps, thanks for this!