Ensure your device is permitted to receive SMS (text) messages. Within the Text-Enabled Number pop-up window, enter your text-enabled device number and select the Send Verification Code button. Enter the verification code that is sent to your device and select Submit. The code may take a few minutes to be received.
If you do not receive the code after a few minutes, you may select the Resend Verification Code button to have another code sent to your device. Any previous codes will be invalidated.
If you need to change the number you provided, you may edit the text-enabled device number and select the Resend Verification Code button to have the code sent to the new updated number you entered. Any previous codes will be invalidated.
Refer to Multi-Factor Authentication for additional information.