When I click the formula button, I don't see the toolbar in the Equation editor.

If you add a formula or equation to your quiz, sometimes the Equation toolbar doesn’t appear within the Microsoft Equation editor.
This is because the Equation toolbar is disabled in your system.

To enable the Equation toolbar:

1. Click 'View' in the top menu of the Equation editor;
2. Enable the 'Toolbar' option in the drop-down menu.