Enter a source URL (your post) and target URL (the post you linked to).
Telegraph will discover the Webmention endpoint of the target URL and send the Webmention for you.
You'll be able to see the progress after you click "send".
Telegraph and p3k are part of the indieweb. To learn more about the indieweb and IndieWebCamp, visit the wiki or join the IRC channel.
Telegraph is built and maintained by Aaron Parecki.