Twitter is also very particular if you don't provide them with your phone number, and are using something like Tor to browse them. There are plenty of only SMS verification services but they will keep bothering you to do a SMS verification *every time*. Having a 2FA with Authy doesn't help at all either.
A Mastodon instance based off Kitakami Reika from THE iDOLM@STER : Million Live! Feel free to talk about anything really. Just be nice, and make it family-friendly! ミリオンライブの北上麗花に興味がある皆さんの非公式マストドンインスタンスです。一緒に親子で楽しめる場所にしましょう!