Custom YAML config file does not work

I am trying to follow the guide https://mongoose-os.com/docs/mongoose-os/userguide/configuration.md

I put custom config conf_schema.yaml into src folder with below content:

[
  ["hello", "o", {"title": "Hello app settings"}],
  ["hello.who", "s", "world", {"title": "Who to say hello to"}]
]

Also, I modified the mos.yaml file:

sources:
  - src/main.c
  - src/conf_schema.yaml

However, after mos build, these properties did not show up in the build\gen\mos_final.yml

I am curious what have I missed?

Thanks for suggestions

The part with conf_schema.yaml is not valid anymore.
Add your settings in the config_schema of mos.yml

  - ["hello", "o", {title: "Hello app settings"}]
  - ["hello.who", "s", "world", {title: "Who to say hello to"}]