Convert Common js to Module js

As even the official docs say it's recommended to use module.js, I've seen some websites still using CommonJS. It might be because there are still legacy systems running, but I think it's better to port to module.js.

Describe the solution you'd like The solution is to port our entire backend project to the module.js system to make it more up-to-date.

Describe alternatives you've considered I don't think there are many alternatives — it's better to go with module.js.

Additional context Setting up CommonJS locally is quite difficult, as it's almost like working with a legacy system.