Is there a code or something? Do I have to buy it to show it here? Do I upload the .tga file to imgur and display it with ?

If you are talking about the head avatar item, no need to upload anything. Just activate it and a miniature of you head will be under your name ingame

I meant display the head avatar item on a post on my head texture shop so that it spins to fully preview it. I've seen professionals do it

Get gimp, 100% free, and there's a animation thing called spinning globe, use that.

Ok thanks.