Item extensions do not appear to be registered for an rss2 feed

[jeromecovington]

I am attempting to add additional fields to an rss2 feed item outside of the core Item but they do not seem to be exposed in the feed.

In my item setup:

    feed.addItem({
      title,
      id: link,
      link,
      description: excerpt,
      date: new Date(date),
      extensions: [
        {
          name: "item_extension",
          objects: {
            "dc:creator": "foo bar",
          },
        },
      ],
    });

Example item xml with dummy data:

<item>
  <title>
    <![CDATA[ My Page ]]>
  </title>
  <link>https://my-site.com/my-page</link>
  <guid>https://my-site.com/my-page</guid>
  <pubDate>Sat, 10 Jun 2023 01:03:37 GMT</pubDate>
  <description>
    <![CDATA[ My description. ]]>
  </description>
</item>