Passkeys feature provide a reliable security for user, which is not possible with old-style two factor authentication such as OTP verification through SMS and email. This feature stores your password as a unique passkey on your device, which can be accessed through biometric authentication. Meanwhile, for setting up a WhatsApp account on your new phone not required too much time, as your passkeys will be stored in Google Password Manager, which is a good initiative by WhatsApp.
Read more: https://techbird365.blogspot.com/2023/10/how-to-setup-passkey-on-whatsapp.html
