Mounting portal to an gmod server

Alright facepunch, I have a issue- I need to mount portal to my server im hosting but have no idea how to do it,
it dose not mount like the other content, -css gmod tf2 ect- and I need some help

can anyone help me get this mounted so I can get this done thanks, I would appreciate it

:edit: I mounted it if anyone ever needs help contact me ill help you mount it