Abiypy electron ebands.py part problem

[Sushiki-suda]

When I want to draw Fermi surface of my materials, I learn from MgB2 Fermi surface drawing. (https://abinit.github.io/abipy/gallery/plot_fermisurface.html) However, I find there is no any data from command "ebands.get_ebands3d()". I check the source file of "ebands.get_ebands3d()", it include command "ElectronsBands3D", however, there is no any contexts in it. I wonder how I can draw Fermi surface by using Abipy. Thank you.