click on the Open JSON file option available on the bottom-left part of the Settings page. If it prompts you how you want to open that file, select Notepad from the available options, and press OK.

If the Open with dialog box pops up for the JSON file, select Notepad in that pop-up and proceed further. Now the JSON file will open in Notepad. There, scroll down, and add "confirmCloseAllTabs ...