Coding Challenge #83: Chrome Extension with p5.js Sketch

I created a Firefox addon using this tutorial. Have a button to start the sketch, but it is not stopping even when refreshing the page. I want to add the logic for stop button, but not finding the same in the vast p5.js library. My code at https://github.com/nabendu82/WebsiteMarker and addon at https://addons.mozilla.org/en-GB/firefox/addon/website-marker/