Log into Arc Server Manager and click on Services > Manage Services.
Find a map service to use
Click on the map service to see its properties.
Click on the Capabilities button.
Copy down the REST URL. It should have a path similar to this: http://<server name>/ArcGIS/rest/services/<service name>/MapServer
In the Lucity Administration tool go to GIS > Connection Strings.
Find the record named DEFAULT and put the URL collected in step 1 into the URL field.
Clicking in a different field will save the change.
Note: For more information about this screen go here.
Settings
In the Lucity Administration tool go to System > Settings > GIS tab.
Make sure the Use ArcGIS Server to persist geodatabase changes from the desktop option is set to TRUE. (It should be by default)
Review the List of emails for notifications regarding failures to update the GIS database, and Send an email if no feature is found in GIS to update settings.
After making all changes click Save.
Note: For more information about these settings go here.