POS users will be able to login to the POS via a pin code and not a username or password. 
Similar to unlocking an iPhone, IWD implemented login logic for POS users to access the system via a pincode.
Each POS user has a Magento admin user account. An additional option “PIN” is available in your Magento Admin Panel -> System -> All Users -> Select specific user -> PIN
PIN must be unique across all admin users.