It's a good idea to check that you've entered the correct phone number. If you find that you have made an error you can use the Change My Mobile Number feature.
You should also check that your device is currently in a good coverage area.
If your number is correct and you are in a good coverage area, you can request the text message be sent again by choosing the Resend Me The Security Code Text Message option available.
If you continue to have difficulties, please Contact Us.