Since you are searching for this information, you may have found out that there is no way for
Vinagre remote desktop viewer to connect to a
Windows Server via
Windows Remote Desktop (
RDP) when a
RD Gateway Server is needed for the configuration.
What we did to make this work was only to install
remmina on our machine using this command
sudo dnf install -y remmina;.
Remmina by default supported the configuration using
RD Gateway Server so we did not have to do nothing more than just use it.