I assume this is for the Math Challenge II-A Fall 2021 course?

After typing your answers in the space (or making a choice in the multiple choice questions), you need to click on the "Next" button at the bottom of the page to get into the next part, and need to click "submit" at the end.  If you don't submit, the status of the quiz will show "In progress", and the teachers will not be able to grade it.