So, I must now go read an understand developing modules. PHP isn't an issue, but the new front-end and js is so much different. I also need to orientate myself with the structure of the code, it has a lot of similarities, but also a lot of differences. Mainly, Dolphin 5 wasn't OOP, where UNA is.

Don't forget to refer to our documentation https://unacms.com/wiki/Introduction ! Especially to the Development part.