You will need to add at least one security contact to your security profile. A security contact is any non-UI email address or phone number that you have access to that can be used to receive a security code and reset your password.
Click on the "new" button to bring up the Security Contact screen. On this screen, you can select to add either an email address or a phone number set up fir either text or voice communication. Please note that if you set your phone number for text service, carrier rates for text messages may apply.
Enter your contact and click the "Send Verification Code" button. This will send a verification email or text message depending on your contact selection. If you input a voice phone number, you will receive a call with your verification code.
Obtain this code and enter it in the new window to "verify" your contact. It will be added to the list and how up with a green background, confirming it is verified. You can verify as many contacts as you would like.