Take a look at this example code at Re: getCurrentStatus error on Ios 11.2.2 on Zebra iMZ320. Though it's about getting the status, the essence is the same in terms of how to connect with the printer through the Bluetooth. This sample code is based on Link-OS SDK for Xamarin for iOS. It uses the same way to connect from Android. Please be aware that we need to specify the Bluetooth MAC address in the API when connecting from Android, while we need to specify the printer's Serial Number in the API when connecting from iOS. Hope this helps.