For future searchers of this question:
You cannot use a module for grade passback. You have to create an assignment with the exact URL of the specific module you want to use.
How to make an assignment viewable AND with a gradepassback URL:
Congratulations! You should now have an assignment a student can take and will feature grade passback.
Here is a very useful video with the entire process; please note I am not the creator. The grade passback section is after the 7 minute mark.