There’s an issue with Twitter now, hope it will be resolved in a few days.
Twitter feeds and “log in with Twitter” do not work at the moment since @Twitter suspended my developer account @vshabanov (like it was with @BazQuxReader one).
I’ve applied for the new developer account for @BazQuxReader. It could take several days for Twitter to review my application. Feeds won’t work until then.
I’ve also filed appeal for suspended developer account. But it took 4 months to unsuspend @BazQuxReader account so I won’t expect it to become unsuspended too soon.
If you can’t log in with Twitter try to sign in with apps username & password.
If you have no email or username please mail support@bazqux.com with your Twitter account name and order ID (if you have one) so I could set up email login for you.