Morse Code is a backup access mode. It allows you to unlock your device using long / short combinations by pressing the power button. Morse Code gives access to your lock without your fingerprint or your phone.
You can set up your Morse Code in the "Lock Setting" section within the Tapplock App. Once Morse Code has been set up, press the Power Button on the lock three times to enter Morse Code mode. The status indicator light should be purple. Under Morse Code mode, you can enter your combination by pressing the power button.