You must have paired your badge reader beforehand.
See : How to pair a Badge Reader with Door Keeper?
Press the central button of your Door Keeper lock motor for 3s. The motor LED flashes WHITE. Enter your 5-digit code on the reader's keypad. Please note that this code cannot start with the number ZERO. 3 beeps will confirm the creation of the code.
You also have the possibility to create and share codes via the application in the Manage access section then new Keyring.