Using R to download data automatically

I want to download all the data in either pdf or excel for each State X Crop Year X Standard Reports combination from this website.

I followed this tutorial to do what I want. Download data from URL

However, I hit an error on the second line.

driver <- rsDriver()

Error in subprocess::spawn_process(tfile, ...) : 
group termination: could not assign process to a job: Access is denied

Are other methods that I could use to download these data?