i cant find the uv map in fab 3d editor

I have a mesh that has two materials with two different UV maps, but I can’t configure it correctly in the fab editor. I can’t find the option to adjust it.

The option should be here but I can’t find it.

on sketchfab it’s very easy to find

This is how it looks in Blender

This setting is basic for creating materials. : (

pls help