That was not what I meant
I was just asking for the specific download link for the file, for example this script will install 8.6 version without problems
# Download file
url <- "https://homepages.uni-regensburg.de/~wit59712/easystrata/EasyStrata_8.6.tar.gz"
pkgFile <- "EasyStrata_8.6.tar.gz"
download.file(url = url, destfile = pkgFile)
# Install dependencies
install.packages(c("Cairo", "plotrix"))
# Install package
install.packages(pkgs=pkgFile, type="source", repos=NULL)
# Delete package tarball
unlink(pkgFile)