My ingress-nginx-controller is stuck in ContainerCreating...when I describe the pod I can see below events type is a warning ...failed mount

MountVolume.setup failed for volume "webhook-cert":  secret "ingress-nginx-admission" not found

I can't find any secret for that namespace .. RKE k8s version: v1.17.4 .. what could be the reason this failed ...and how to fix ...