> install.packages("ggplot2")
Warning in install.packages :
  unable to access index for repository http://cran.rstudio.com/src/contrib:
  cannot open URL 'http://cran.rstudio.com/src/contrib/PACKAGES'
Installing package into ‘C:/Users/admin/Documents/R/win-library/3.6’
(as ‘lib’ is unspecified)
Warning in install.packages :
  unable to access index for repository http://cran.rstudio.com/src/contrib:
  cannot open URL 'http://cran.rstudio.com/src/contrib/PACKAGES'
Warning in install.packages :
  package ‘ggplot2’ is not available (for R version 3.6.1)
Warning in install.packages :
  unable to access index for repository http://cran.rstudio.com/bin/windows/contrib/3.6:
  cannot open URL 'http://cran.rstudio.com/bin/windows/contrib/3.6/PACKAGES'
Warning message:
In download.file(mirrors_csv_url, destfile = mirrors_csv, quiet = TRUE) :
  InternetOpenUrl failed: 'A connection with the server could not be established'

Thank you.