Hi Cheah chin hooi thanks for reaching out. Can you try to tap on the 3 dot icon at the top-right corner and tap on Desktop Site/View. This will allow you to view the course page in desktop view so you can see the quizzes. This is a known issue when accessing the course on a mobile browser, you can instead download the OpenLearning app to access the course.
If you need further assistance, please email email@example.com. Thank you.