This Wiki helped me out a lot.
Os = Ubuntu Mate (Release 20.04 LTS (Focal Fossa) 64-bit)
Release 20.04 LTS (Focal Fossa) 64-bit
bluetoothctl version = 5.53
Procedures I followed on the Terminal:
$ bluetoothctl agent on
$ sudo bluetoothctl --monitor
# scan on
# pair xx:xx:xx:xx:xx:xx ...(Here input your device's address from the scan results)
- You will be presented with a pin request ... usually 1234 or 0000(For speakers and/or headsets) should work. If you are pairing with a phone you can use any four digit pin since you are gonna input the same on your device...
`[agent] Enter PIN code:` 0000
# connect xx:xx:xx:xx:xx:xx (again your device's address)
# trust xx:xx:xx:xx:xx:xx ... (for future auto-reconnects)