Hi there!!!
As you can see the shader does the black outline on the mesh…
(I know you can do this outline using post process effect material and custom depth, but this option doesnt work for mobile)
I have done some research and come up to this conclusion:
The World Position Offset input allows for the vertices of a mesh to be manipulated in world space by the Material(This shader just “extrude” each vertex along his normal vector)
Theres a content example that extrudes vertex, but i dont know how to make it outline my object. (Content Examples Sample Project for Unreal Engine | Unreal Engine 5.1 Documentation)