how to edit the deployment of nginx in kubernetes code example

Example 1: kubernetes get deployments

# Get pods in default namespace
kubectl get deployments

#Get Pods in my-namespace
kubectl get deployments -n my-namespace

#Get Pods in all namespaces
kubectl get deployments --all-namespaces

Example 2: k8s roll back to previous deployment

kubectl rollout undo deployment/app --to-revision=2