For SE/TIP courses where students have HackerRank assignments and Leetcode assignments, make sure that you take these assignments within the extension period. There is no need to submit manually in the course portal. Taking these assignments is sufficient. Make sure that you have used the same email address with what you used when applying to the course.
For all other courses, submissions are made in the course portal using the Submit Button in the Project tab. Make sure to fill out each field. For the GIF part, ensure that your recording has a *.gif extension for it to be accepted.