neon

If you write something like “@nick, how are you?” this plugin will search for @nick’s url in the comment list of the current post and will convert his/her name to a link.

Twitter style links

This plugin allows you to add Twitter style links to comments.

Eric-Oliver Mächler

Expand your Twitter-Name @something in your Posting with Twitterlink http://twitter.com/something
Manual:
If you want to link a Twittername write @twittername in your post. this Plugin will it automatically link
This Plugin is GDPR & DSGVO secure

Twitter Expander

Expand your Twitter-Name @something in your Posting with Twitterlink http://twitter.com/something

Twitter style links vs Twitter Expander