The tutorial is outdated and wrong. It is unfortunate that you guys do not revalidate them time by time.
The Ingress "ingress-echo" is invalid:
* spec.rules[0].host: Invalid value: "echo.": a lowercase RFC 1123 subdomain must consist of lower case alphanumeric characters, '-' or '.', and must start and end with an alphanumeric character (e.g. 'example.com', regex used for validation is 'a-z0-9?(\.a-z0-9?)*')
* spec.tls[0].hosts[0]: Invalid value: "echo.": a lowercase RFC 1123 subdomain must consist of lower case alphanumeric characters, '-' or '.', and must start and end with an alphanumeric character (e.g. 'example.com', regex used for validation is 'a-z0-9?(\.a-z0-9?)*')