I'm using Mac OS Big Sur and my setup has an external display. When using any other application on my mac, I can use Window > Move to <display name> to move windows to my external display and back. Because I can map a keyboard shortcut to this function, I use this all the time to move my windows around so I don't have to take my hands off my keyboard.

Firefox however seems to be the only application that doesn't implement this for some reason. Has any other Mac user found a way around this?