Hi,
After Sign In to the Simlink application, make sure you install Simlink Plugins to Flight Simulator. And In the case of MSFS, you do not need to install Simlink Plugins.
To check Simlink plugins are installed correctly, just start the Flight Simulator and the Simlink application will automatically start with the Simulator.
Please feel free to inform us about the issue.
TR,
Vishal Ahir
Navigraph