If it is your first login attempt, kindly wait for some time as the delay can be due to network congestion, and try logging in again or try restarting your device. The first OTP is sent to verify your mobile no. and subsequent OTP’s will be sent to both your email address & mobile no.
We strongly recommend to Bind Google 2 Factor Authentication to avoid network delays in the OTP delivery and also further secure your account.
If none of the above steps work, please contact customer support.