otpExpirationDuration property
The OTP expiration duration, can be used to display a timer, and show a resend button, to resend the OTP.
Firebase does not document if the OTP ever expires, or anything about it's validity. Hence, this can be used to show a timer, or force user to request a new otp after a set duration.
Defaults to FirebasePhoneAuthController.kAutoRetrievalTimeOutDuration.
Implementation
final Duration otpExpirationDuration;