You can create a new User without having to leave the Scheduler screen, by clicking on the + symbol at the bottom of the screen > User.
A drawer will open from the right side of the screen, and you will be able to add the User information required for the new User account, and click Save.
You will also be given a prompt to let you know that you have successfully added a new User, with a link to their profile so that you can edit their permissions if required.