.Net 5 Kestrel behind Kubernetes Load Balancer Unrecognized HTTP Version
You need to decide if you want to terminate https on your application or before that. I would suggest that you use Ingress instead of LB type service to expose your service to external world. That way you can configure https termination on the ingress it self and the app would remain http based with no need to configure certs, encryption etc. on the app it self, although you would still need to configure ingress properly.