Usually you'll receive the phone verification code within seconds, but sometimes there is a delay. If you restart the app and try again it should work. Once you enter the code, that will complete the phone verification. Verification codes can only be sent to cellular devices.
Please be sure to reach out to your service provider for more information on why you're unable to receive text messages with short code or “Premium” messages on your device. If you have T-Mobile or Sprint, you will not be able to receive the code until you reach out to your carrier (at no cost to you). For security purposes, the only way to access your Jackpocket account is by receiving the verification code by text.