Hello @HannaVance 

Thank you for contacting the Instructure Community. Unfortunately, there is no way to require a student to complete the same module multiple times without duplicating it. You can have them re-do certain assignments or get a specific score on a quiz before they can move on, etc. But you'd need multiple modules to make them complete everything within it. Here is the Canvas guide:

https://community.canvaslms.com/t5/Instructor-Guide/How-do-I-add-requirements-to-a-module/ta-p/1131