In reply to Using site as pseudo-Mastodon.

There are a few ways that WordPress can interact with Mastodon: either directly using ActivityPub as a protocol or indirectly by either copy/pasting content from your site or syndicating by way of API to a separate Mastodon account.

The easiest is the one I recommended using ActivityPub and Nodeinfo. ActivityPub will make your WordPress user account look to others like a standalone Mastodon instance (that is, on par with other federate-able instances like mastodon.social, gnusocial.net, peertube.live, etc.) In your case your instance will likely only have one user (or perhaps a few based on how many accounts are on your WordPress install). The plugins shouldn't require any set up or configuration beyond what name you give your own WordPress user profile(s). The ActivityPub plugin should cause a "Fediverse" heading to appear in your WordPress admin dashboard at https://example.com/wp-admin/profile.php, though you should replace example.com with your own website. Mine indicates that I have a profile identifier of @chrisaldrich@boffosocko.com, which when put into a Mastodon search will show you my account which you can follow. People who reply to your site/posts by ActivityPub protocols using Mastodon or similar software will cause the messages to appear on your site in the comments section. The downside of the process is that there isn't an ActivityPub reader for you to easily follow and read others' posts yet (at least to my knowledge), though most Mastodon sources support RSS and thus feed readers, otherwise you might try out one of the IndieWeb social readers. After you've been using it, you'll notice that on your site at /wp-admin/users.php?page=activitypub-followers-list, you'll find a list of the people following you. The NodeInfo plugin adds some additional metadata to your site to help it show up in the Fediverse properly. Some of this is generally invisible to the average user, but you can test if it's working properly by looking for your data on a service like https://the-federation.info/wordpress which should show your website and its statistics.

I would suspect that in your case that if you set the two plugins up, you should be able to search for and find your WordPress site on Mastodon by searching for @danicotillas@comunicacionabierta.net.

The other way to interact is to use a plugin (like Mastodon Autopost, Mastodon Auto Share, or possibly others?) that is tied to a separate Mastodon account and which uses their API to physically cross post your content. This means you have to have and maintain a separate Mastodon (or similar) account and duplicate copies of your content. If you want replies and notifications back from that account you'll need to have Webmention support and set up your Mastodon account with Brid.gy and do some additional configuration there.

I saw your error notice on Twitter (https://twitter.com/danicotillas/status/1518977229048406022). It may have occurred because you have the Webmention plugin installed and had already sent me a webmention or potentially because you don't have a properly set up h-card for your site and the parser on my end isn't finding any data for your username, homepage url, or your avatar. In any case, you'll notice at the bottom of the error message it says that your webmention was successful and indeed I did receive it.