You can install pkgdown from CRAN, or its development version from GitHub, and find more information from its GitHub repository (https://github.com/r-lib/pkgdown).
install.packages("pkgdown") # Or the development version ::install_github("r-lib/pkgdown")devtools
After it is installed, you can call the function
pkgdown::build_site() in the root directory of your source package. It will build a website to the
docs/ directory, which can be turned into an online website via GitHub Pages or Netlify.