Add minimum time to course lessons, so they can't be completed earlier

I'm using WordPress with the free LearnPress addon. When setting up a lesson in the WordPress backend there is an option called lesson duration. The lessons are all between 2-10 minutes each. We want the lesson duration to be used as the minimum time the lesson needs to be open before it can be completed. We'd like a timer within the button text, or next to it that counts down the lesson duration time. After the duration it would then allow the student to click the Complete button.