What mapping options do I need in the JSS to get Apple School Manager to work?

you can add a custom user extension attribute to the JSS and it will populate into the user criteria dropdown. you should read Integrating with Apple School Manager to Support Apple’s Education Features Using the Casper Suite

under the section Matching criteria for importing users it says

*It is recommended that you match "Source System Identifier" from Apple School Manager with the student ID number in the JSS. One way to do this is to create a user extension attribute that collects the student ID number in the JSS. (For more information on how to create a user extension attribute, see the User Extension Attributes section in the Casper Suite Administrator's Guide.) The default criteria selection matches "Email (JSS)" with "Managed Apple ID" from Apple School Manager. Note: Imported users from Apple School Manager cannot be matched to users with manually entered information in the Roster category of user inventory information. This results in duplicate users.

@mickgrant I see how to create the user extension attribute, but I am not sure how to add the data to that field. We already have a field in the JSS called department, and we populate it with ID number. Do you know the best way to copy that data over? Or is there a way to map it? Thanks