Portal Gun Add on Help

I’m having trouble installing a portal gun addon to Gmod. I download it and add it to the addon folder but I can’t find it anywhere. Please help!!

The link to the add on:

This is unbelievably old, and will probably never work again.

I doubt there is a single portal gun addon that works anywhere on the internet.

Ailin95 is working on one.
He has a few youtube videos showing it.

Normally I wouldn’t do this, but…

Pics. Pics, or it didn’t happen.