You can register your Mastodon instance as well at the end of the script and install it.
/*
register('Local', 'http://localhost:3000', {
sensitive : false, // or true to hide an image
spoiler_text : "", // any text before "SHOW MORE"
visibility : "" // "public", "unlisted", "private", "direct", or "" for your default
});
*/
register('Octodon', 'https://octodon.social');
register('MSTDN.JP', 'https://mstdn.jp');
register('Pawoo', 'https://pawoo.net', {
sensitive : true
});
})();