How do I add a news feed to a Matrix channel?

Authors:

You must be an Admin in the channel. Find this out by going to the channel and selecting Room info –> People, or clicking on the little circle images of people in a channel. Admins can make other admins.
Go to Room info –> Extensions –> Add extension –> Feeds
Under Subscribe to a feed, add a URL from this GTN feeds listing. Make sure that it ends in .xml. For example, https://training.galaxyproject.org/training-material/topics/community/feed.xml would provide updates on any community-tagged GTN materials into the Matrix channel.
Under Template, change the existing text to the following: $LINK: $SUMMARY
Provide a reasonable name, and then hit Subscribe!

Details from Matrix are here: https://ems-docs.element.io/books/element-cloud-documentation/page/migrate-to-the-new-github-and-feeds-bots