Hi Japneet,
You must have an object of quiz, create quid id(Int) and also create 2 one to many association to account entity
1.unattemped(*)_participant_quiz
2.attemped(*)_participant_quiz
create deeplink which can open quiz for users. this deeplink should take quiz id as param , share this deeplink to users
Now in admin side setting, select user whom you want to take quiz, and put that person in association unattemped_participant_quiz then in deeplink by quiz id retrieve quiz object and from quiz object retrieve unattempted people list and retrieve current user account & check if current user is in unattempted associaton or not
if it is there show quiz page otherwise not.
when user has attemped quiz put that person in attemped_participant_quiz association and remove from unattended association.
Hope it helps!