To lock course lectures,
From the dashboard, go to PRODUCTS, select COURSES and choose the required course.
Click on COURSE CONTENT to list all lectures.
Select the lecture that needs to be locked. Click on RULE BASED CONTENT DRIPPING.
You can lock the lecture based on the percentage of course completion or the number of days from the subscription date. You can also set up a rule, for example, the learner should go to the next video after successful completion of the previous one. That can be done by choosing the lectures from Add rules option and after adding the rules Click on SAVE button.