Connecting a Bluetooth printer to Linux Mint

The following is how to connect a Bluetooth printer. The key is using a Manual URI with the MAC address without semicolons as the hostname.

Easy when you know how.

This give a good summary of the bluez-tools:
https://fixmynix.com/bluetooth-in-linux-with-bluez-and-hcitool/

root@Spectre ~ # rfkill list
lists the various adapters, including hci0

root@Spectre ~ # hcitool scan
lists the various devices available, including H470. Note its MAC address:
00:1A:0E:EC:22:A2

https://www.cups.org/doc/network.html
The AppSocket protocol (sometimes also called the JetDirect protocol, owing to its origins with the HP JetDirect network interfaces) is the simplest, fastest, and generally the most reliable network protocol used for printers. AppSocket printing normally happens over port 9100 and uses the socket URI scheme:
socket://ip-address-or-hostname:port-number

This was the solution:
https://help.ubuntu.com/community/BluetoothPrinterSetup

Kicker → Printers → Add Printer → Select a Printer to Add → Manual URI → Connection →
bluetooth://001A0EEC22A2/