Why can't I upload an OBJ, ZIP, or FBX with the correct textures?

[Majestic]

I'm attempting to get a Fortnite character model into Mixamo through Blender. In Blender, the textures look fine, so I export as an OBJ to start. Obviously, OBJ's don't have textures, so how might I be able to add a texture post-mixamo in Blender?

After OBJ's didn't work, I try zipping the given MTL and OBJ files together, and it comes out with a strangely lit model that also doesn't export out of Mixamo with any of the correct tectures. 

Finally, FBX's. These are confusing as all heck. I exported one of my character models as FBX and imported it to Mixamo. It came out with a perfectly textured head, but no textures anywhere else.

Any help is appreciated. I've spent 3 days working something out.

[Ussnorway]

the shinny one is because your textures are the wrong kind and the Fbx with the head is because the model is set up wrong i.e, the body will have one background colour and the head a different background colour... thats just from looking at the screengrabs you posted

what now? = share the files and I'll take a look... should be pretty easy to fix