You don't.
Seprate your work life and your personal life.
There's nothing wrong with advocating for FOSS alternatives; but you don't get to decide what you can or cannot use on work devices, that's up to your employer. You should not be entering personal info/performing personal tasks on work devices.
If you're unwilling to perform work with the tools (software) your employer provides/requires, find a new job. Refusing to do the work or tampering with the equipment provided is a great way to get fired.
For school; personal laptop. Or again strictly school tasks on their devices.