First, when posting code to this forum, please wrap your code in triple backticks (```).
See https://discourse.gohugo.io/t/sharing-code-in-the-forums/8968.
Second, the documentation you cited is in YAML format, while the code in the GitHub repository is in TOML format. If your site configuration file is config.toml, use the TOML fomat. If your site configuration file is config.yml, use the YAML format.
Third, Wowchemy has a dedicated discussion board. Please post your question there. See:
https://github.com/wowchemy/wowchemy-hugo-modules/discussions