Chatgpt-plugin auth question and yaml file

Since a chatgpt-plugin would be made available via chatGPT (3.5 and/or 4) user interface, why the following yaml sample document specify “” for domain name instead of “”? I find it confusing.

In addition, for the “Plugin Manifest” (ai-plugin.json file), what value should one use if he/she wants to use “api-key” for “auth”?

openapi: 3.0.1
title: TODO Plugin
description: A plugin that allows the user to create and manage a TODO list using ChatGPT.
version: ‘v1’