How to debug a failure to install the hello_service from the tutorial

I am running Home Assistant 2023.2.1 provisioned in a docker instance running on an Unraid server.

I am attempting to follow the instructions described at “Integration Services”.

It looks very simple, yet I have failed and I am unable to determine any way to establish what has gone wrong.

I created the file custom_components/hello_service/__init__.py. In the interest of completeness, this is the file as I have it.

DOMAIN = "hello_service"

ATTR_NAME = "name"
DEFAULT_NAME = "World"


def setup(hass, config):
    """Set up is called when Home Assistant is loading our component."""

    def handle_hello(call):
        """Handle the service call."""
        name = call.data.get(ATTR_NAME, DEFAULT_NAME)

        hass.states.set("hello_service.hello", name)

    hass.services.register(DOMAIN, "hello", handle_hello)

    # Return boolean to indicate that initialization was successful.
    return True

I also created custom_components/hello_service/manifest.json

{
    "domain": "hello_service",
    "name": "Hello Service",
    "documentation": "https://developers.home-assistant.io/docs/dev_101_services",
    "iot_class": "local_push",
    "version": "0.1.0"
}

Lastly, I modified my configuration.yaml so that it looks like this. Note the last line which is new. If I remove the hello_service: line, then the configuration is accepted by the check system.

# Loads default set of integrations. Do not remove.
default_config:

# Load frontend themes from the themes folder
frontend:
  themes: !include_dir_merge_named themes

# Text to speech
tts:
  - platform: google_translate

automation: !include automations.yaml
script: !include scripts.yaml
scene: !include scenes.yaml

hello_service:

Now, when I then visit “Developer Tools” and select “CHECK CONFIGURATION”, I receive the following output.

Integration error: hello_service - Integration 'hello_service' not found.

Sadly, home-assistant.log offers no new information.

What have I missed?

After you created all of the files above in the custom_components directory did you restart Home Assistant before adding the hello_world: entry in the configuration.yaml file?