By default, when the user enters a phone number, we'll send a verification code or magic link using SMS. You can add the option for your users to receive the verification code or link as a WhatsApp message.
In your dashboard > Branding, select the WhatsApp checkbox for the Magic Link Form tab and OTP Verification Tab.
WhatsApp requires that your application implement explicit user opt-ins to deliver messages over WhatsApp.
To do this, we provide the WhatsApp Button Configuration > Subtitle to explicitly inform your users that they will be receiving a verification code via WhatsApp.
The default value for the Subtitle is "If you choose to login with WhatsApp, we will send a WhatsApp message to this number with a verification code"