Situation:

When E2020 kids don't pass a quiz in 2 times they are locked out - how to unlock them?

Solution:

In the web administrator login, select the student and the class and that will open the gradebook. Look down through the tree for the quiz and click on it. To the right is a box with the heading "selected assignment." Under that heading are some links. Click on allow optional retakes and you will see a screen that lets you assign additional retakes.