I installed a Firefox Extension and need to customize a keyboard shortcut it uses. Apparently this needs to be done by modifying the Extension's manifest.json
From Mozilla:
Each keyboard shortcut is defined with a name, a combination of keys, and a description. Once you've defined commands in your extension's manifest.json, you can listen for their associated key combinations with the commands JavaScript API.
The problem is that I can't define anything because the .json is read-only in my browser window, and I don't know where (or if) it can be accessed outside of the browser through macOS Finder.
Here's a related question: How to access the manifest.json file of a Firefox extension? but it doesn't go into how to edit it.
Maybe I've missed something?