Thanks Don for your reply.
I work with MapSuite Desktop Edition 5.5.0.0
At the beginning of this topic it is stated
"it seems the license key do not need to be provided when in Desktop application."
and in my case it worked well without key.
I first looked for an explanation in the Google API and the cause could be using an older version of API (?).
I wondered which version is used by calling :
ThinkGeo.MapSuite.DesktopEdition.GoogleMapsOverlay (5.5.0.0)
Now if a key is really necessary, do you know how to get into the Google console?
Thank you.