Thanks for your patience, the 500 error is now fixed!https://twitter.com/TeamYouTube/status/980889488531521536 …
You can add location information to your Tweets, such as your city or precise location, from the web and via third-party applications. You always have the option to delete your Tweet location history. Learn more
It'll likely be the end of April before you receive an update. Applications are still in a backlog and we're working to review them. Thanks for your patience in the meantime.
Twitter may be over capacity or experiencing a momentary hiccup. Try again or visit Twitter Status for more information.