For small tests, pre- and post-processing with R, you can start an interactive sessions on the login nodes. All other R jobs have to be submitted through the batch system. You can submit an R job (inputfile.R) in batch mode with the following command:
sbatch [Slurm options] "R --vanilla --slave < inputfile.R > outputfile"
Here you need to replace [Slurm options] with Slurm parameters for the resource requirements of the job. Please find a documentation about the parameters of sbatch on the wiki page about the batch system. In this case, stdout is redirected into "outputfile".
Please note that from version 4.0.2 the command line option --slave has been renamed to --no-echo