https://techcrunch.com/2023/01/12/third-party-twitter-apps-tweetbot-twitterrific-echofon-down/

People using third-party Twitter clients are facing a number of issues including unable to log in and access Twitter feeds. Tweetbot, Echofon, and Twitterrific, three popular third-party Twitter apps, confirmed the issues and noted that they are not sure what has triggered the glitch.

Tweetbot and other clients are experiencing problems logging in to Twitter. We’ve reached out to Twitter for more details, but haven’t heard back.