This applies to students, teachers and administrators.
If your school has a custom login, click here.
Resetting your password is an easy process. First, you should try to log in as normal. Go to https://testy.me/login, find your school. When the login page asks for your login password, instead click "Forgotten your password?". In the box that appears, enter your username or email address.
An email will then be sent to the email address associated with your Testy.me account - it'll probably be your school email address. Find and open that email, and click the link in the email to continue.
In the page that appears, you can then type in a new password for your account. After that, you should be able to log in as normal.