There are several methods of remotely connecting a computer with multiple screens.
For example, here is one of them: Press Win+R on your keyboard to involve the Run window and type: mstsc.exe /multimon. The “Use all my monitors for the remote session” box will be checked automatically, but for this time only. Neither the connection properties nor your credentials will be saved on this machine. So if you plan to have more remote desktop sessions here, or this is one of your RDP servers, better go for one of the other two methods, see here https://www.helpwire.app/blog/remote-desktop-dual-monitor/ In addition, it is necessary to take into account other nuances, such as Windows versions on the connected computers, etc.