With the recent hacking of Twitter accounts, Twitter has stepped up the security with the introduction of two-factor authentication when signing in. However, unlike those that you have seen in Google, Twitter’s two-factor authentication (2FA) is simpler.
First, you will need to activate this feature. It is found on the Twitter setting page. Access Twitter on your browser to activate this feature. Once done (you will need to provide a mobile number), when you sign in, you will need to enter another set of code that will be sent to your mobile phone. Here is a video on how it is done.
I tried to enter my mobile phone number but was given this error.
I will try again tomorrow. Anyway, I think it will be a pain if you are overseas and no access to mobile phone.