When you run the Simlink installer a green icon is placed in the Windows systray bottom right (or macOS Status bar top right of screen):
Press the uparrow to display icons.
Left mouse click on this to get a Status page:
Right mouse click on this to bring up the first menu.
Click on Plugin Settings.
For Simulators other than MSFS, Navigate to your flight simulator, ensure the correct path is set.
For example, for X-Plane, click the … button and navigate to your X-Plane folder where x-plane.exe is located. Press on Install Simlink to place the Simlink module in X-Plane. Ensure you have a green tick.
MSFS does not have this module so doesn’t appear in Plugin Settings as per FAQ - Simlink provides Charts Moving Map support for MSFS
Simlink will now be started when you start your flight simulator.