Looks like the packages are not installed in a proper way. I do not know a lot about problems with that. One package that seems to be missing is fs but maybe there are more.
You could try first:
install.packages("reprex")
and I guess dependecies (like fs) should be installed. If you want to make sure that fs is installed:
install.packages("fs")
to install these packages.
However, as I said, maybe there are further problems with the installation, and you would need help from somebody else on community.rstudio.com.