If you see the following message when trying to pair the printer, it can be resolved in a couple of steps.
Fixing Connection Unsuccessful
If you see this error, it's likely the printer is already paired with the iPad. You will need to forget the device.
On the iPad go to Settings
Under My Devices you should see QL-820NWB0182 (or similar)
Press the 'i' Icon
Select Forget Device
Press OK to confirm
Go back to Jomablue Lite and attempt to pair the printer.