No module named diffnext_v2

[abilalk02]

I am trying to run the wurstchen-stage-B.ipynb file and I encounter the following issue.

from diffnext_v2 import DiffNeXt, EfficientNetEncoder, Prior
No module named diffnext_v2.

Where can I find this module?

I bypassed this issue by importing DiffNeXt, EfficientNetEncoder and Prior from the modules.py file. However, my image reconstructions are terrible. I am only getting random results. These are the only changes I made while running the .ipynb file.
Any guidance would be much appreciated