Early versions of these TCUs didnt support bluetooth telephone calling despite the bluetooth logo on the box. It just supported bmw assist. You need to check realoem and ensure the part number is a later version.

Also you will need to check your vehicle has phone prep. If it does then it will have a microphone in the headliner and potentially a bluetooth antenna in the center console. These should all terminate in a batch of cables in the trunk area and connect to the tcu. Check to make sure you have these.