How do I confirm my phone number?

Here's how to add and confirm your phone number:

1. Go to your Settings.   
2. Under the "Phone Numbers" section, click + Add New (or Change next to the phone number you want to confirm if you're updating your number). Stay logged in and don't exit from the window.
3. Enter the phone number and select the phone type.
4. Click Add phone number.
5. Choose Text you a code or call you to confirm.
6. Enter the confirmation code and click Validate.