If we navigate to RAS Console > Farm > VDI > Desktops, and see if we can add any Desktop without having any VDI template added, the Add button is going to be grayed out:
Remote PC static VDI Host differs from actual Hypervisor-based VDI solutions since it does not require any template VMs to work.
It is purposed primarily for adding the existing machines or machines that are going to be spun up in the nearest future.
Adding Desktops manually from Desktops tab can be performed only when there is a template to choose from.
First, the machine should be added using VDI Provider Properties:
Once the machines are added, Desktops will automatically show up: