To verify or change your phone number, go to your Account > Edit Profile > Basic Information. Select your country code from the drop-down menu, then enter your area code and phone number into the box. It's best to use a cell phone, but you may also use a land line, if you're in an area with weak reception.
You'll have the option to receive text message notifications when you get a call request.
You can then manage what notifications you receive or disable text message notifications altogether by going to your Account > Settings > Notifications.
