free courses

I want to set up a course where students can take some portions for free. As you introduced the free unit I think this can be possible. SO I set up a testing course here: https://krishipathshala.in/all-courses/testing-courses/#component=course the course settings: https://ibb.co/gJfjGJ6 Please check the image for clarification. but the student can't access the course without payment( here is only the free portion I am saying). whenever some one click on the take this course it transfer to the checkout page for payment. how can a student get access the free portion without the payment