Hey @GotetiPeeyusha, in order to receive your certificate of completion, each curriculum item must be marked as complete. Double-check the course curriculum in the course player to make sure each lecture and course item has a checkmark beside it and is marked as complete.
For steps on how to manually mark a lecture as complete, please click here.
That said, keep in mind this is the Udemy instructor community. For any questions or concerns about the student's side, please reach out to firstname.lastname@example.org. The team is best equipped to answer these types of questions.