Using helm to deploy into Kubernetes cluster, version does not match

[whoszus]

Hi all,
I am using helm to deploy the fn into my Kubernetes cluster but suffered a version miss-match, via https://github.com/fnproject/fn-helm;
how could I get the Right version? My Kubernetes version is 18 btw

[whoszus]

Error: validation failed: [unable to recognize "": no matches for kind "Deployment" in version "extensions/v1beta1", unable to recognize "": no matches for kind "Deployment" in version "apps/v1beta1"]