How to Add a Rubric to an Assignment
Whammo Zammo, it is done.
I would have included links to the appropriate Guides, but it sounds like you are already familiar with those.
I hope this helps,
@sclark3 , @kmeeusen has definitely given you the step-by-step (whammo-zammo )! Your screenshot shows that you're in the edit mode of the assignment, and that might be the source of the confusion; the + Rubric button does not appear in the edit assignment view. Also, if it happens that you have created an assignment of the External Tool submission type, even after you've saved, you won't see the + Rubric button; it disappears for External Tool types. You'll need to create the assignment and save it first with a different submission type, then add the rubric, and then re-edit the assignment to switch the submission type to the External Tool of your choice.
Hi @sclark3 - I wanted to check-in with you and see how you were doing with adding rubrics to your assignments. Were you able to make Canvas work the way in which you hoped? Did the ideas shared by @kmeeusen and/or stefaniesandershelp you? For now, I'm going to mark this question as "Assumed Answered" but that will not prevent you or anyone else from commenting on the thread. If you have a few minutes, it would be awesome to hear an update!