Not sure what search you're using, but Googling `xcancel redirect` gave me plenty on the first page. You could be stuck in a search bubble. Maybe try searching in private browsing mode?

This one is manifest v3: https://chromewebstore.google.com/detail/xcancelcom-redirect...

This userscript (despite the name) also redirects to xcancel: https://greasyfork.org/en/scripts/450008-twitter-to-nitter-r...