How is a department added to a course offering?

A course offering is created using the CreateCourseOffering data structure (below) but this has no entry for "Department", which is included in the CourseOffering data structure, when the course offering is pulled from brightspace. How is department added to the offering via the REST API? I see no way in the reference at https://docs.valence.desire2learn.com/reference.html.

Thanks.

 

Course.CreateCourseOffering

{

"Name": <string>,

"Code": <string>,

"Path": <string>,

"CourseTemplateId": <number:D2LID>,

"SemesterId": <number:D2LID>|null,

"StartDate": <string:UTCDateTime>|null,

"EndDate": <string:UTCDateTime>|null,

"LocaleId": <number:D2LID>|null,

"ForceLocale": <boolean>,

"ShowAddressBook": <boolean>,

"Description": { <composite:RichTextInput> }, // Added with LP API v1.26

"CanSelfRegister": <boolean>|null // Added with LP API v1.28

}