@fishmonger1969 ...
It sounds like you might be a student taking a course in your school's Canvas environment. Is this correct? If so, I'm thinking that the self-proofing checklist is something you'll need to ask your instructor about. As far as I know, Canvas does not have a self-proofing checklist built in to the platform itself, so I bet this is something your instructor has created in the course for you and your classmates. You can contact your instructor directly in Canvas by taking a look at this Guide:
How do I get help with Canvas as a student?
Hopefully you'll be able to get some help from your instructor soon so that you can complete the assignment. Good luck! Please keep us posted here in the Community. Thanks!