Hello @paola_page ...
When you are logged in to your Canvas course, does the "Grades" course navigation button on the left side of your screen have a crossed-out eye icon next to it? If so, that means the button is hidden from students. You will need to enable that button. Check out the steps in this Guide: How do I manage Course Navigation links?.
Please let Community members know if you have any other questions about this. Take care...stay safe...be well.
