Hi #Twitter, this “browser” is the current Thunderbird release, a mail and RSS client. Its capabilities are no different from Firefox 78. How about you detect Gecko rather than detecting Firefox?
Better yet, do feature detection instead of UA sniffing: https://developer.mozilla.org/en-US/docs/Web/HTTP/Browser_detection_using_the_user_agent
Just realized that the Twitter server responds with “400 Bad Request” here. That’s IMHO a very unconventional way of saying: “Your request is fine but I don’t like the client you are using.”
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