How to assign a user to a note record in Campaign sequence

This may seem like a silly question but how do you assign a user to a note record in a campaign sequence?

The docs say mention it in line 6 but I’m still not seeing how to do it. I’m not wanting to notify the user but rather just assign it to them.

Currently, the note record reads [unassigned user] for the assigned user field. Annotation 2020-03-16 104631