I'm assuming you're on windows?
I'm not on Windows so can't confirm, but I just copied the address for the download link for 4.1.0 from the page below. I'd be surprised if altering the R version in the address doesn't do what you need.
"https://cran.r-project.org/bin/windows/base/R-4.1.0-win.exe"
(EDIT: There's also a link to download 'previous releases' at the bottom)
https://cran.r-project.org/bin/windows/base/