How can I share files from my phone to a school Chromebook?

Honestly, getting around school firewalls is tricky. If your Chromebook is managed by your school, you might not have much luck unless you talk to the IT department. They can help clarify what's allowed.

It’s tough with these restrictions. Typically, if the policy is set at the account level, sharing the file won’t help because the device checks the rules before letting you do anything. It may be better to stick to content you know is permitted or just wait until you can use a personal device later.

Have you tried using the Localsend app? It lets you share files between devices as long as both are connected to the same WiFi network. It could be worth a shot! Just make sure to set it up properly on both devices.