Trying to create a project page namespace

Hello everyone, I am trying to create a project page namespace and I am not entirely sure where or how to create this. So I want: project-name.gitlab.io The examples I’ve found online show you how to create a group namespace but will end up with a a url like this: group-name.gitlab.io/project.

Could someone kindly share with me how to do this: https://project-name.gitlab.io

Thanks in advance!