Games require a webserver to run properly in Chromium-based browsers due to security restrictions. While developing, ct.js hosts a local web server for your game. You can run your project, then click “open in external browser” icon, and then test the opened link in different browsers to see whether it works in them. (Actually, you don’t need to do it, because the built-in debugger is built on Chromium :D)
So if it works in ct.js debugger, it will work. Upload your exported game to some web server (e.g. here on itch) and it will work there as well. Otherwise, use desktop builds if you want to run games offline.