Greetings, yourfavoritefrog.
I see that you're using the Cellular Calls feature of Continuity between your iPhone and your MacBook Air. The problem is, you can't answer a phone call on your Mac. I'm happy to help.
System requirements for Continuity on Mac, iPhone, iPad, iPod touch, and Apple Watch -- Make sure your iPhone and Mac meet the system requirements.
Use Continuity to connect your Mac, iPhone, iPad, iPod touch, and Apple Watch -- Make sure the feature has been set up correctly.
With the iPhone Cellular Calls feature, you can make and receive calls from your Mac, iPad, or iPod touch when those devices are on the same network as your iPhone.
Use iPhone Cellular Calls with any Mac, iPhone, iPad, or iPod touch that meets the Continuity system requirements. It works when your devices are near each other and set up as follows:
- Each device is signed in to iCloud 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 iPhone, go to Settings > Phone > Calls on Other Devices, then turn on Allow Calls on Other Devices.
- On iPad or iPod touch, go to Settings > FaceTime, then turn on Calls from iPhone.
- On Mac, open the FaceTime app, then choose FaceTime > Preferences. Click Settings, 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.
Let me know how that goes, and take care!