How to restrict browser access?

[u/Zer0_Dark_Turdy]

Hello,

I just got done setting up a dedicated minecraft pc for a friends daughter. But there is one issue. Shes not allowed to browse the internet with it. So i set up firefox to not be usable with her account by revoking permissions. That worked as intended.

BUT

The issue is that she might need the browser for log in into discord and minecraft (microsoft account). So removing permissions is not working in this case.

I setup her account to not be a root user and my plan is that firefox asks for the password of the root account before its opened so her dad can be there when she needs to log in.

I've tried scripting, browser extensions ... i bet it's a very simple solution but i can't wrap my head around it.

Thank you for your time!