None of these releases contain R. On Windows, pip can install the same R Portable (v3.2.3) as in the main stream sDNA if given the optional R dependency:
pipx install sdna_plus[learn,R]
On Linux, R (plus optparse and Car) must be accessible in the host environment. E.g. to install it on Ubuntu:
sudo apt-get update
sudo apt-get install -y r-cran-optparse r-cran-sjstats
pipx install sdna_plus[learn]