The original addon is here: https://ankiweb.net/shared/info/1362209126
This "fork" was made primarily for personal use but I am sharing it because it may be useful to someone else.
With heavy assistance of ChatGPT, I have added the ability to import multiple decks at once by inputting multiple URLs. There is also an option to import them straight into a parent deck by specifying its name in the menu.
Sometimes, it doesn't import a deck on the first try (but that doesn't happen very often). It may be a little buggy (but seems fine after strenuous testing) and I cannot give any promises about future fixes. Give the __init__.py file with the error info to ChatGPT for help.
I will publish the code when I get the time to do so.
Updated GUI Screenshot