How to track every time learner resumes a session

Hello,

We are required to ask the learner to register themselves every time they start/resume a course using a QR code. It's fine when putting it at the beginning of the course, but the issue is when they stop and then come back in the middle. They may forget if we just put it behind a button. We would like to have the code graphic flash on the screen every time they resume a session. Is there a way to track when they resume?