brew install issue - setting user argument

[stuartrapop]

Issue: missing instructions on how to set user argument on install

stuartrapoport@Stuarts-MacBook-Pro frontend % brew install onesignal-cli            
==> Fetching onesignal/cli/onesignal-cli
==> Cloning https://github.com/OneSignal/cli.git
Updating /Users/stuartrapoport/Library/Caches/Homebrew/onesignal-cli--git
==> Checking out tag 0.0.7
HEAD is now at 9e947b1 Merge pull request #42 from OneSignal/fixing_include_copying
HEAD is now at 9e947b1 Merge pull request #42 from OneSignal/fixing_include_copying
==> Installing onesignal-cli from onesignal/cli
Error: An exception occurred within a child process:
  ArgumentError: user srapopor doesn't exist