Welcome to the FNF Zenith modding API!
ModPacker: It's there to replace hscript at the cost of compiling the source code which is a single hx file, along with a few files (such as embed.xml) to a zfmp file, and the ability to make it the entire mod pack that you can store your raw embedded data in.
You may not release the source of your Friday Night Funkin' Zenith mod publicly. Read the license for more details.
Just compile modpackTemplate with your custom assets.
I hope you enjoyed this!