Your chromebook has been deprovisioned, meaning it is no longer under the control of District 126. Your student account is, however. You will need to sign out of that account and in with a personal account to not encounter any other restrictions.
Despite being removed from district control, you may notice that your chromebook still references zbths.org/students.zbths.org. You can remove this by fully wiping your device, following these directions:
Press Esc++Power. A yellow exclamation point (!) or "Please insert a recovery USB stick" is displayed.
Press Ctrl+D to begin Dev mode, then press Enter. Wait until the next screen.
Press Space, then press Enter. The Chromebook deletes its local data, returning to its initial state. This can take approximately 40 minutes.
When the transition completes, press the space bar, then press Enter to return to Verified mode.
If you wish to keep your student data and transfer it to a personal account, please follow the procedures here: