• Follow the entire Pairing process of this guide from the Arch Linux wiki.

• If you've already paired with a keyboard before you only need to run this in terminal (lines with # are what you type in):

# bluetoothctl
[bluetooth]#

[bluetooth]# power on
Changing power on succeeded
[CHG] Controller 06:05:04:03:02:01 Powered: yes

[bluetooth]# pairable on

[bluetooth]# scan on
Changing pairable on succeeded

[K380 for Mac]# devices
Device F4:73:35:8E:B1:7F K380 for Mac
Device F4:73:35:93:7F:9D Keyboard K380
Device 71:E3:81:9B:FC:20 71-E3-81-9B-FC-20
Device 54:11:33:FA:24:3F 54-11-33-FA-24-3F
Device BE:16:AE:00:20:F7 MELK-OA10   F7
Device 6B:8C:DD:FC:B1:77 6B-8C-DD-FC-B1-77
Device 5A:55:D8:31:3E:3C 5A-55-D8-31-3E-3C
Device B0:D2:78:B6:47:6D Sbb88cc3eaa738db2C
Device 08:65:F0:3D:89:CA LEDnetWF0200273D89CA

[bluetooth]# connect F4:73:35:8E:B1:7F
Attempting to connect to F4:73:35:8E:B1:7F
Connection successful