If you want to ensure a quiz is only marked as complete once the learner has received a passing grade, click on the icon of three vertical dots next to the quiz and click on Edit settings.
At the bottom of the Edit settings page, click on Completion conditions and select Add requirements to reveal extra options.
Select Receive a grade and then Passing grade to ensure that the activity will only be complete once your learners have passed the quiz.
Make sure that you have set the passing grade in the Grade drop-down menu. (By default this is set at 0.)
(Alternatively, if your learners don’t need to pass the quiz to complete your course but you still want the quiz to count towards course completion, select the View the activity option.)
Then click on Save and display.
There should now be a checkbox on the homepage alongside the quiz you added completion tracking to. The system will add a tick to this box when the activity has been completed.