When signing up, you will be asked to enter your institution code. Your teacher should be able to provide this for you. If you don't know it, you can select skip and enter it at a later date by following the below steps.
- Select Profile in the drop-down menu next to your profile image
- Scroll to License, underneath Current License choose Click here to join your institution if you have an institution code
- Enter your code, the institution name will appear. Select Join