Seeded Learning Assignment Alert / Voluntary Assignments

Summary:

Does the seeded alert to notify learners of a learning assignment fire for voluntary assignments or only required assignments?

Content (required):

We created an initiative where a course offering was voluntary assigned to a large number of learners. While I can see they were enrolled in the offering, no one received the assignment notification.

Does it only send when it's a required assignment and not recommended or voluntary?

Version (include the version you are using, if applicable):

21D

Code Snippet (add any code snippets that support your topic, if applicable):