Why does the "sections" property in Python wikipedia package return an empty list?

Question

I can get content of a Wikipedia section if I ask for a specific section, for example:

import wikipedia
print(wikipedia.WikipediaPage('Sleep Well Beast').section("Promotion"))

but when I try to get all the sections, I get an empty list, why?

print(wikipedia.WikipediaPage('Sleep Well Beast').sections)

According to documentation, this should give a list of sections:

user_16588059 · Answer

You need to install the wikipedia_sections libary using

pip install wikipedia_sections