how to get rid of this error

Anyone knows how to get rid of this error i have installed r tools a d everything but every single time I try to install a package same error or version error I have r.4.0.3

> install.packages("dplyr")

Warning in install.packages :

unable to access index for repository https://cran.rstudio.com/src/contrib:

cannot open URL 'https://cran.rstudio.com/src/contrib/PACKAGES'

Installing package into ‘C:/Users/pankaj/Documents/R/win-library/4.0’

(as ‘lib’ is unspecified)

Warning in install.packages :

unable to access index for repository https://cran.rstudio.com/src/contrib:

cannot open URL 'https://cran.rstudio.com/src/contrib/PACKAGES'

Warning in install.packages :

package ‘dplyr’ is not available for this version of R

A version of this package for your version of R might be available elsewhere,

see the ideas at

https://cran.r-project.org/doc/manuals/r-patched/R-admin.html#Installing-packages

Warning in install.packages :

unable to access index for repository https://cran.rstudio.com/bin/windows/contrib/4.0:

cannot open URL 'https://cran.rstudio.com/bin/windows/contrib/4.0/PACKAGES'