i found the file, it is un-editable
It's a JSON file, so you'll have to open it in a text editor specifically. If you're on windows, right-click it, choose "open with," and select a text editor like Notepad. (Notepad is better than Microsoft Word here.) Once you get in there, you'll see some lines that look like this:
"screenwidth": 1920,
"screenheight": 1080,
Change those numbers to the resolution you'd like the game to be. Then save the file. Make sure to retain its .json suffix.