why do we need to open port 6443 in GKE Firewall master rules

[ganga-relyanceai]

I was trying to understand why we need to add firewall rule to allow port 6443 in GKE to make the KEDA work properly. Can you please explain the reasoning behind it. I have cheked the documentation. It only mentions to add port but no reasoning though

[ganga-relyanceai]

any code that I can look to get a proof. I need to convince IT/Security team why we need to open 6443 port