How to mark course as completed

I am having two courses, one is a Prerequisite for the other. I am testing now, took the first course and completed it but the second course still not accessable for me!! How to tell ope-edx that the course is completed?.
I made sure that all the assignment dates are within the start/end dates of the course. Also, I tried to adjust the end date of the course to yesterday or even before that, but still the second course is still locked.