Disable "addons.mozzilla.org"


I have an unusual question:

I have a parental control that I use with a whitelist. But on FF, I can’t get block access to to FF addons (CTRL+SHIFT+A). I don’t mean downloading them, but even accessing the addons themselves. Even if I block “addons.mozilla.org”, it still comes up?

Any help would be much appreciated!

Thanks in advance…

P.S. I wonder if there is a way of doing it via about:config, but even so, I can’t block anyone from altering it back anyway.

Sorry for the trouble, I have figured it out!