This error is likely happening because you are signed in to your personal or another IPS Student's Gmail/Google account. When you must be signed in with your child's IPS Google Account.
If you are on a mobile device such as a tablet or phone you will have to switch between Google Accounts on the device. Please see the screenshot below for visual instructions. Also note that the location and steps to switch accounts on a computer are quite similar.
1. Tap/click your profile photo (top right corner)
2. Tap/Click Add another Google Account OR Select the other account if already signed in
3. Login using your child's IPS Google Account details OR continue to your child's Google Classroom if signed in.
Please note that you can switch between users the same way on the device which can help if they are using a shared phone, computer, or tablet.