your iphone is not configured to allow calls using this mac

Hey there, and welcome to Apple Support Communities macette1976,

We can certainly understand your concern and see you came to us from the article If FaceTime isn't working on your Mac.

We recommend checking out these steps for more information on how to make and receive calls on a Mac to see if it matches up with your procedures.

" Make and receive phone calls on Mac or iPad

With the iPhone Cellular Calls feature, you can make and receive phone calls from your Mac or iPad when those devices are on the same network as your iPhone.

Set up iPhone Cellular Calls

Make sure that your Mac, iPhone, and iPad meet the Continuity system requirements.

Your devices must also be near each other and set up as follows:

• Each device is signed in with the same Apple ID.
• Each device is signed in to FaceTime with the same Apple ID.
• Each device has Wi-Fi turned on.
• Each device is connected to the same network using Wi-Fi or Ethernet.
• On your iPhone, go to Settings > Phone > Calls on Other Devices, then turn on Allow Calls on Other Devices.
• On your iPad, go to Settings > FaceTime > Calls from iPhone, then turn on Calls from iPhone.
• On your Mac, open the FaceTime app, choose FaceTime > Settings (or Preferences), then select Calls From iPhone.

If your carrier supports Wi-Fi calling on other devices, you can set up those devices to make and receive calls even when your iPhone isn't turned on or nearby. Learn about Wi-Fi calling.

Make and receive phone calls

After setting up your devices, you can make and receive phone calls on your Mac or iPad whenever the iPhone is nearby and on the same network as the other device.

• The steps to make a call vary with the app you're using. In most cases you can simply tap, click, or Control-click the phone number that you see in your app. Then tap or click a phone button , or choose a call option from a menu. You can also make a call directly from the FaceTime app. Learn more about how to make and receive phone calls on Mac.
• To answer a call, use the notification that appears on your Mac or iPad when someone calls your iPhone. You can answer the call, send it to voicemail, or send the caller a message.

To stop getting calls on one of your devices, just turn off the Calls from iPhone setting on that device. See the setup section above for details. "

For additional information, check out this link: Make and receive phone calls on Mac or iPad - Apple Support

These steps will help ensure your device is working with ease and can fix common issues like the ones you’re experiencing.

Kindest regards!