Error response from daemon pull access denied for microsoft/iis, repository does not exist or may require 'docker login'

in my collage class a lab im working on tells me to
“Type docker pull microsoft/iis and press Enter to download the Microsoft container image that includes IIS. This step may take several minutes, depending on the speed of your Internet connection.”
but when i do that i get the error
"error response from daemon : pull access denied for microsoft/iis, repository does not exist or may require ‘docker login’
i know it cant be the login it because ive that on the step before. Ive done some research and i was wondering if miscrsoft/iis still available or what im i doing wrong that i get that error