$pipenv install requests (problem on Mac)

Hello,

Trying to $pipenv install requests, but getting this:

usage: install [-bCcpSsv] [-B suffix] [-f flags] [-g group] [-m mode]
[-o owner] file1 file2
install [-bCcpSsv] [-B suffix] [-f flags] [-g group] [-m mode]
[-o owner] file1 … fileN directory
install -d [-v] [-g group] [-m mode] [-o owner] directory …

Not sure how to proceed. Any suggestions would be most welcome!

Thanks!

D