conda - How to install R packages that are not available in "R-essentials"?

I use an out-of-the-box Anaconda installation to work with Python. Now I have read that it is possible to also "include" the R world within this installation and to use the IR kernel within the Jupyter/Ipython notebook.

I found the command to install a number of famous R packages: conda install -c r r-essentials

My beginner's question:

How do I install R packages that are not included in the R-essential package? For example R packages that are available on CRAN. "pip" works only for PyPI Python packages, doesn't it?

Now I have found the documentation:

This is the documentation that explains how to generate R packages that are only available in the CRAN repository:

Go to the section "Building a conda R package".

(Hint: As long as the R package is available under use this resource. See here:

alistaire 's answer is another possibility to add R packages:

If you install packages from inside of R via the regular install.packages (from CRAN mirrors), or devtools::install_github (from GitHub), they work fine. @alistaire

How to do this: Open your (independent) R installation, then run the following command:

    install.packages("png", "/home/user/anaconda3/lib/R/library")

to add new package to the correct R library used by Jupyter, otherwise the package will be installed in /home/user/R/i686-pc-linux-gnu-library/3.2/png/libs mentioned in .libPaths() .