I was finally able to access the dashboard by editing the Traefik deployment and adding --api.insecure to spec.template.spec.containers[args]. Would be great if there some logs visible anywhere indicating that this was the issue all along! Why is it necessary to set this to insecure?
I'm still unable to access the whoami service as described in the blog post, and again there are no logs to help me understand why, it's just a black box to someone new like me.