You can find the R scripts for spatial modelling in the rscripts folder.
Every R script is composed of two files: a *.rsx file with the R code and a *.rsx.help file with instructions on how to use the R script.
To use an R script, you must save both *.rsx and *.rsx.help files in your local QGIS rscripts folder. On Linux machines, this generally is located at:
/home/<your-name-here>/.local/share/QGIS/QGIS3/profiles/default/processing/rscripts
On Windows machines, the QGIS rscripts folder is generally located at:
C:/Users/<your-name-here>/.qgis/processing/rscripts
