Overview
When you update the CircleCI server, you can see the following kind of message:
# Only create this secret if mongo is externalized and no existing secret was provided
Answer
This is just a comment message, not an error message. It can be printed out when you run the helm upgrade command with --dry-run option, which can show commented lines:
helm upgrade circleci-server oci://cciserver.azurecr.io/circleci-server --namespace circleci-ns-poc --version 4.3.13 -f /home/ec2-user/values.yaml --dry-run=server