The pgxl chart does not apply the kubernetes secret, therefore we must first apply that. To apply the secret run:

kubectl apply -f ./pwd_secret.yaml

Then you sync with helmfile,

helmfile sync

Example secrets config,

apiVersion: v1
kind: Secret
metadata:
  name:  pgxl-passwords-collection
type: Opaque
data:
  # You must base64 encode your values. See: https://kubernetes.io/docs/concepts/configuration/secret/
  pgpass: "bGFtYQ=="

For encoding to base64,

printf "mypass" | base64

Note, do not use echo, it will add a newline.