I can’t add a feed

Sorry, but CyberSEO can not add it because it’s not an RSS feed. It’s an XML one, which has a different structure. If you open its source, you won’t find the standard <item>…</item> blocks there. Even a browser doesn’t show it as an RSS tree.

Thanks for your quick answer, it’s nice to see you are helping your users.
Sorry to insist: I have changed the url to change to the kind of feed from Atom to RSS: https://jazzcafefm.blogspot.com/feeds/posts/default/-/Nuevos%20Albumes%20de%20Jazz%20Internacional?alt=rss.
This is the way to have rss from blogspot according to Google: https://support.google.com/blogger/answer/97933?hl=en.
In this new url you can find the <item>…</item> structure, but still the result is the same. You can see the image of the result here: https://imgur.com/YtDtBO4

Thanks a lot for your help.

álex.