In order to sign in to the accounts, users can also use a security key, but they will need to first turn on the 2FA methods like SMS code or an authentication app.
Twitter to Enable Two-Factor Authentication
— Twitter Support (@TwitterSupport) December 2, 2020
And coming soon: the option to add and use security keys as your only authentication method, without any other methods turned on. — Twitter Support (@TwitterSupport) March 15, 2021 It is important to mention here that the hardware security keys are more secured than conventional authentication processes. These keys are available through physical keys connecting PC via USB or Bluetooth. There is no need to enter a code on the phone. It will make difficult for hackers to access users’ account. Twitter said, “Secure your account (and that alt) with multiple security keys. Now you can enrol and login with more than one physical key on both mobile and web. And coming soon: the option to add and use security keys as your only authentication method, without any other methods turned on.” Recommended Reading: Twitter Aims to Launch “Space” Globally By April