1. Go into the course that you want to edit.
2. Click More from the horizontal menu under the course title at the top.
3. Select Course completion from the menu. 
4. Click Expand all located on the right.
5. Scroll down to the section titled "Condition: Activity completion".
6. Toggle on each activity in that section that you want to require as a condition to complete the course.
7. Click the Save changes button at the bottom of the page.