Matplotlib ModuleNotFoundError: No module named 'mpl_toolkits.basemap'

Question

I was trying to create a plot of a map with matplotlib, and I tried to run this code:

from mpl_toolkits.basemap import Basemap
import matplotlib.pyplot as plt

map = Basemap()
plt.show()

but I get this error:

ModuleNotFoundError: No module named 'mpl_toolkits.basemap'

I have read many answers to similar problems, but none of them have worked for me.

(Python basemap module impossible to import, ModuleNotFoundError: No module named 'mpl_toolkits.basemap')

I am running Python 3.7 on macOS 10.15.5 using PyCharm