Upgrade AP management IP no internet

So the title says it all. I have a management network that does not have internet access but the control can see it and the control box has internet. The APs are layer 3 adopted. I am trying to upgrade these remotely and it acts like it is going to go for it just to go nope no thanks. I assume the management IP range will need internet access for the upgrades to work ?

This sub has been very helpful in the past thanks. I feel like a noob asking this but I always assumed the controller had the software bins and pushed them down not just sent them the web download link.