AKS upgradation from 1.28.3 to 1.28.5 to 1.29

Hi Team,

I have deployed AKS version 1.28.3 in my environment, now customer wants to upgrade to 1.29.0, my understanding is that before migrating to 1.29.0 we should be upgrading to 1.28.5.
I have deployed this AKS cluster using Terraform code, when we do the upgradation, we don’t want to see any interruptions to the Application or the running Pods.
Please let me know how we can achieve this, also share me if any step by step procedure is available.

Also, for AKS node pool OS upgrade how we can perform the upgradation.

Regards,

D Thennarasu