Yes! You can create an extension after an assignment due date and time has passed, and, in most cases, do the same for assessments (quizzes and tests). You can find instructions on providing extensions here.
If your student hasn't yet started their assessment, or if they have remaining attempts, you can give them an extension.
If a student has already completed all their attempts on their assessment and you want to let them retake it, you can either add additional attempts for the individual student using these instructions or reset the assessment to let them back into the assessment. Either reset only their last attempt to give them one more try, or repeat the reset process to allow them multiple retakes. Please note resetting the attempt will delete previous assessment data.