Hallo Marc. If I understand you right, you are using a laptop - and this laptop only have one connection for a screen?

No matter if you have a normal PC or Laptop, you need enough connections to the amount of screens you want to connect, AND the graphics chip/card needs to support the amount of screens, the resolutions and screen update HZ you plan to use.

I have a relative old PC with a nvidia based card (760 gtx) that can drive 2 samsung 4K screens, one with HDMI and one with Display-port.

On none of the laptops I have, it is possible to connect 2 4K samsung screens.
One of the laptops I have is a Elitebook G6 (generation 6). I have a docking station for it, but the Intel chip cannot handle 2 time 4K, but lower resolution is possible - even to 3 screens (like full hd)

There are many different docking stations and connections, just check, you need the RIGHT amount of ports, AND a graphics chip that can handle the output!