If you want to create modded jobs on PC you need to buy a tool.
You have to have GTA for PC and a PC powerful enough to run the game of course.
A regular laptop will not cut the mustard.
It doesn’t matter which platform R* launcher/steam/epic.
I use a tool called Xenvious.
The VIP version costs $25.
If you want to make modded jobs on console that is a well guarded secret that no one, including myself, is willing to give up.