A USB security key plugs into your computer's USB port and functions as an extra layer of security that's used in Online Banking to increase limits for certain transfer types.
USB security keys are an optional alternative to SMS-based one-time security codes if you do not have access to a U.S. mobile phone number or can't receive texts to your phone.
USB security keys can be purchased at many online and trusted tech retailers and typically cost between $18-$50. Just search for 'USB security key' and make sure the key you choose is FIDO-certified.
You will be able to register your USB security key beginning June 21.
When prompted for your USB security key, all you need to do is tap the button on the key already inserted into your USB port, allow the browser to read your device and continue with your transfer.
Once your USB security key is set up, it serves as an extra layer of security for adding transfer recipients to your account and for extra security at sign-in.