Hi Ale,
First of all, remote users can connect to their Windows client computers through the Remote Desktop Services (RDP) running on the Pro and Enterprise editions (but not on Home/Single Language).
But there is a restriction on the number of simultaneous RDP sessions – only one remote user can work at a time.
That's why if you try to open a second RDP session, a warning appears asking you to disconnect the first user session.
Let's focus on the RDS itself by design. The number of simultaneous RDP connections is limited rather by the license (then by any technical aspect).
Therefore, this restriction does not allow to create a terminal RDP server based on the workstation that can be used by multiple users.
Microsoft’s logic is simple: if you need a Remote Desktop server – buy a Windows Server license, RDS CALs, install and configure the Remote Desktop Session Host (RDSH) role.
In such case, I'd like to recommend you deploy RD Session Host.
It implements feature which multiple users concurrent working and share the same RD Session Host server.
You could refer the following steps to deploy the Remote Desktop servers in your environment.
https://learn.microsoft.com/en-us/windows-server/remote/remote-desktop-services/rds-deploy-infrastructure
Best regards