I have been trying to download to produce the book. I had a number of problems with various packages when I had R 4.0.0 so upgraded to R 4.1.0 and reinstalled all packages. Finally failed as follows:

PS C:\Users\dsco036\Documents\Research\Books\Sievert> Rscript -e "devtools::install_github('cpsievert/plotly_book')"
Using github PAT from envvar GITHUB_PAT
Downloading GitHub repo cpsievert/plotly_book@HEAD
Error in utils::download.file(url, path, method = method, quiet = quiet, :
download from 'https://api.github.com/repos/cpsievert/plotly_book/tarball/HEAD' failed
PS C:\Users\dsco036\Documents\Research\Books\Sievert>