Why can't the program load the magnetic field?

[epectation]

Hello everyone, I am using pywarpx to perform 2D axisymmetric plasma simulations. When adding a magnetic field, I used ‘picmi.AnalyticAppliedField’ to load an axial LC-circuit-driven magnetic field. However, when I checked and read the value of the magnetic field, I found that the result was 0. I asked AI and tried many times but could not solve it. However, using ‘picmi.AnalyticInitialField’ to load the initial magnetic field works correctly. I hope someone can answer my question. Attached is my own code.
plasma.py