import sklearn.datasets
pendigits = sklearn.datasets.load_digits()
mapper = umap.UMAP().fit(pendigits.data)
umap.plot.connectivity(mapper, show_points=True)

Above code gave me the error below.

umap.plot requires pandas matplotlib datashader bokeh holoviews scikit-image and colorcet to be installed

The solution is as below.

pip install umap-learn[plot]
import umap.umap_ as umap
import umap.plot

1st one will make a clear of error.

I upload self-answered question as nobody gave a solution in Stackoverflow.

Hope it helps you.