I tried following the instructions provided in the link Savin but it doesn't fix it. Also the k8s we are running is 1.22 I only see these two deployments related to argo

~ ❯❯❯ kubectl get deployments -n argo
NAME                                      READY   UP-TO-DATE   AVAILABLE   AGE
argo-argo-workflows-server                1/1     1            1           257d
argo-argo-workflows-workflow-controller   1/1     1            1           257d

When I see the argo workflows related to the flow which should send notification, I see these two notifications related step in PENDING

NAME:flow-gqb5h.hooks.notify-on-failure   
ID: flow-gqb5h-2770537874   
TYPE: HTTP
PHASE: Pending

NAME: flow-gqb5h.onExit   
ID: flow-gqb5h-2581194255   
TYPE: HTTP
PHASE: Pending