I read this article about overriding a final grade: How do I override a student's final grade in the New Gradebook? 

However, I don't see the "Advanced" tab that allows me to select the check box for grade override.

I also noticed that there is a comment that says "To enable the final grade override, learn how to manage course features."

However, in following that link, it is unclear what needs to be activated in the settings in order to enable the grade override checkbox.

Does this mean that I am unable to do this feature? Or is there a selection I am missing? Thank you for any assistance.