Twitter has announced that it will soon stop supporting SMS based two-factor authentication (2FA) for users that are not subscribed to Twitter Blue. Users will have up to March 20 to disable text-based login authentication codes on their accounts, according to the microblogging service. This means that several users who rely on receiving SMS codes to protect their account will have to subscribe to Twitter Blue. For those who do not want to subscribe, Twitter will continue to support alternative 2FA methods at no extra cost. While Twitter has explained that the reason for shutting down free access to SMS based 2FA was because the phone-number mechanism was abused by “bad actors”, the microblogging service’s post also says that access to SMS-based 2FA for Twitter Blue subscribers “may vary by country and carrier.” If you don’t want to pay Twitter a hefty monthly fee — Twitter Blue costs up to Rs. 900 a month in India — for SMS based two-factor authentication to protect your account, you can switch to a more secure option to protect your account via authentication apps. You can download apps like Authy, Google Authenticator, Microsoft Authenticator, and our favourite, the open source Aegis Authenticator before following the steps below.How to enable app-based two-factor authentication using third-party apps. Visit the settings section on the Twitter website on your computer. Click on Security and account access > Security > Two-factor authentication. Disable the Text message option, if it is enabled on your account. Now select Authentication app > Get started. Open the authentication app that you downloaded, and scan the QR code displayed on the Twitter website. Enter the six-digit numeric code displayed on your authentication app to confirm the setup process.