Great question today
I’m trying to get the port forwarding button working and it doesn’t seem to be creating the port forward. Also, I have other links added but they don’t automatically convert the URL from the service name to the hostname as is implied in the docs. (per Adding Application Links to the Dashboard | Replicated Docs)
My advice would be to start with this example and make sure it works, adding kots-app, k8s-app, and nginx to your application temporarily, then tweak it one thing at a time ( you can only have one kots-app a time though, so you may need to merge your files). Note that while this works well for NodePort and ClusterIP, its not currently usable for LoadBalancer services.
https://github.com/replicatedhq/kots-field-labs/blob/main/labs/lab00-hello-world/manifests/k8s-app.yaml#L8-L9
https://github.com/replicatedhq/kots-field-labs/blob/main/labs/lab00-hello-world/manifests/kots-app.yaml#L10-L13
https://github.com/replicatedhq/kots-field-labs/blob/main/labs/lab00-hello-world/manifests/nginx-service.yaml
https://github.com/replicatedhq/kots-field-labs/blob/main/labs/lab00-hello-world/manifests/nginx-deployment.yaml