Amazon and AT&T have teamed up to allow AT&T mobile customers the ability to make and receive phone calls through Alexa devices. AT&T calling with Alexa works by first linking your existing AT&T mobile number to your Alexa account, which is done in the Alexa app under Settings > Communications. Once linked, you’ll be able to say “Alexa, call [NAME]” to place calls, where [NAME] is someone from your contacts, and incoming calls will ring on your Alexa device where you can say “Alexa, answer” to pick up the call.
With your AT&T number linked to Alexa, all incoming calls will ring on your Alexa device, even if you’re not nearby or your phone is off. If you want to stop them from ringing, you can set your Alexa devices to Away Mode, which prevents it from ringing. It’s also possible to create routines that control when you can receive calls through Alexa. There’s additional info on AT&T’s site.