For an online quiz — one submitted to a server-side script — there is usually a requirement on the student to enter his/her name and ID. PDF forms can create a field that is required, but the PDF viewer does not check for required fields until the data is submitted to the server. In this case, the student must go back and enter the required information.
For an online quiz, this is a problem. You can only end the quiz once (submit the quiz once). If the submission is interrupted by the need to fill in required fields, the student cannot simply resubmit immediately, he/she must retake the quiz and then re-submit. This is unacceptable to the student to have to do this. Therefore, there is a need to check for the required fields as the student begins the quiz, that is, when he/she first presses the begin quiz button. The student is not permitted to start the quiz until the required info is entered.
Try to demo file, source file is attached to the pdf: quiz1_req.pdf
A related article is Checking username and password.
When submitting to a server-side