Your problem is that your zip contains ANOTHER folder inside of it. It's a common mistake, I did it with my first pack, a simple error of an extra folder. To help you out, the correct layout should be this:
(Insert Name Here.zip)
bin
mods
config (optional but recommended)
(anything else such as options.txt or servers.dat)
Your was this:
modpack.zip
PixelTechPackForTechnic
bin
mods
config (optional but recommended)
(anything else such as options.txt or servers.dat)
