How do I enable an iPhone to pair by Bluetooth to a MacBook?

Objective: tether an iPhone -- iOS 10.3.3, by Bluetooth to a MacBook Pro -- macOS 10.13.2.

.

Attempted:

• MacBook > Sys Prefs > Bluetooth > On and discoverable. Sees iPhone.

• iPhone > Settings > Bluetooth > On. Does not see MacBook.

• MacBook > Sys Prefs > Bluetooth > Double-click iPhone.

• MacBook sends iPhone an invitation to pair.

• Offer accepted on iPhone.

• iPhone > Settings > Bluetooth > Other Devices > infinitely shows MacBook with spinning toothpick wheel.

• iPhone > ... Bluetooth off.

• iPhone > ... Bluetooth on.

• MacBook > issue request to pair.

• iPhone > Accepts request.

• iPhone > now sees MacBook in ... > Bluetooth > My Devices. Not Connected.

• i Phone > single click MacBook in My Devices. Alert: Connection Unsuccessful. "MacBookName" is not supported. Only option: Forget Device.

How do I enable an iPhone to connect by Bluetooth to a MacBook?