Hi Henk,
Welcome.
The Charts for macOS download includes Charts for macOS and Simlink.
You should see the two actions required (drag and Install) when you run the installer.
You access Simlink and Plugin Settings etc via Simlink Icon top right macOS Status Bar:
Check the X-Plane path is correct in Plugin Settings as per FAQ - Simlink Install and Systray
Please let us know how you get on.
Cheers
Ian