Hi baltobernie. You go to the SYNC screen in your vehicle. Then...Off the top of my head, go to "Settings", then "About SYNC". It will list your SYNC version, NAV maps version etc. Don't forget to scroll down if necessary.
The latest NAV maps version available is NA 2 21.
You can check for available SYNC and NAV map updates for your vehicle here: https://www.lincoln.com/support/sync-maps-updates/
Let us know how you make out and good luck.