Simple communication between the phone and stm32wb

Is there some kind of example of using stm32WB in the same way as HM-10 BLE.  I need to communicate between controller and mobile phone. The simplest solution seems to be serial communication.

Maybe someone have any example How to read and write value to custom Characteristick in service mode from code ? I saw an example but I am able to exchange only 2 bytes per transmission