Recipient to use for Instructors in Alerts Composer

Summary

What recipient expression sends an alert to instructors?

Content

Hi,

I'm trying to determine what recipient expression to use to send instructors a notification from a resource alert. I've tried a handful of options but none of them work.

This is something I've tried - ${AlertUtils.person(learnerLearningRecords.selectedCourseOfferings.offeringPrimaryInstructor.personNumber).PersonNumber}

This is what works for regular learners - ${AlertUtils.person(learnerLearningRecords.assignedToId).UserName}

Has anyone been able to configure a resource alert that sends the notification to instructors?

Thanks,
Alex