Change keyboard shortcut keys (specifically Cmd-Shift-P)
I'm using Firefox 78.0.2 (64-bit) on Mac OS 10.15.5. One of the main websites I use is based on Eclipse Theia which is essentially VS Code in the browser. It works fine except that the main shortcut for Theia is Cmd-Shift-P and everytime I press it it opens a new private window. I need to change open new private window in Firefox to something else (Cmd-Shift-N ideally) to match Chrome so I can use Cmd-Shift-P as expected in Theia. I've tried searching the forum and the web but can't find the solution.
How do I make this happen?