Please perform some checks before requesting for OTP again:
1. Ensure you have a good network coverage.
2. Check your spam setting / block sender / blacklisted sender / block short code and make sure G2G is not blacklisted.
3. Make sure the email address you provided is valid.
4. Check your spam/junk folder and other folders like Promotions/Social/Updates.
5. If you have antivirus application installed, switch it off or uninstall it temporarily and request for the OTP again.
6. Make sure you have sufficient inbox storage space to allow new messages to be received.
7. Try changing your SIM card to a different device and request for the OTP again.
8. Restart your device and request for OTP again.