I wanna buy something from a seller but it won't allow me to put the sP in the trade. The seller asked me to do the trade but I can't because there is no section for me to put my sP in first

I'm seeing it there. :o

Have you scrolled down and checked under your items?

never mind, it's all sorted.

edit: Thanks for the help :)

I don't think you can create a trade with just sP in it.