find anything with this exact issue. I have custom armor textures I want to import as resources,

This is my first post here, and I am still working on my first mod. Sorry in advance if this is a silly question, I've looked around the forums and couldn't find anything with this exact issue. 

I have custom armor textures I want to import as resources, but when I try to do so (workspace -> resources -> texture files -> import textures -> import armor texture), I get this window: