For setup instructions please see the fabric wiki page and fabric language kotlin wiki page that relates to the IDE that you are using.
This template has several improvements for the modding workflow compared to the fabric template, but the main one is the fact that it is already integrated with the Kotlin language. Also with ModMenu and ClothConfig already embedded, with easy settings to edit at any time without complications.
This template is available under the CC0 license. Feel free to learn from it and incorporate it in your own projects.