By far, the most common reason users do not receive an SMS verification code is because they mistyped their mobile number during registration. 

If you do not receive a verification code within a minute of pressing "Send", restart the registration process from the beginning and make sure that you correctly enter your mobile number. Occasionally, the SMS verification system may also experience a delay or error, but this is very rare.

If you are sure you entered your number correctly and you still do not receive a code via SMS, create a Support Ticket and someone from Frontive Support will contact you soon.