Users of a project are the mobile devices accessing the project, such as phones and tablets. So when the documentation mentions a 'User' it is not an actual person, but a unique mobile device.

Users must be allocated to a project before launch. This can be done automatically or manually, depending on your preference.
Simply hit the toggle switch alongside the allocation mode to change this.

If automatic allocation is turned on, then any user with the valid token and PIN information can launch the project.
This will automatically deduct a credit from your LaunchPad account. If you do not have any credits remaining in your account then the automatic allocation will fail, falling back to manual allocation.

When automatic allocation is disabled, any user who attempts to launch the project will be logged and await your manual approval via the LaunchPad website.

Once the user is approved, it is allocated and the project can be launched again by that user by entering the project token and PIN again.