Before Pairing your device, make sure your Tecla Shield is in the desired mode. If you are not sure what mode you need check here: Tecla Shield modes.
If you are not sure how to change modes check here: Mode Change Instructions.
1. Pair your Tecla Shield: Go to Settings > Bluetooth. With Bluetooth enabled, you should see the Tecla Shield DOS listed under Available devices as TeclaShieldDOS-XXXX (where XXXX is a random sequence). Click on it. After a few seconds, TeclaShieldDOS-XXXX should be under Paired Devices and appear as Connected