Ensure you are using the email associated with your school's Gabadoo account, there is only one email that can be used to sign in. Ask your school's Gabadoo Admin if you are unsure of which email it is.
2. If you have the correct email, try to reset the password by click on Forgot Password. A password reset email will be sent to the email associated with your school's account.
If this doesn't work email support@gabadoo.com and include any relevant information