Issue with quizes and lessons

I’ve built a course and attached it to the quiz I created, but still, I cannot access the course after clicking on continue, it sends me to a “404 error” page.
also when I click on the quiz link from my WordPress pannel it sends me to the actual course, and I can’t click continue to go on.
I tried the same process on incognito but still— the same error.

The page I need help with: [log in to see the link]