How to set Tx power level in 802.15.4 example code

We are developing wireless communication via MAC 802.15.4 . We used your sample code of Mac_802_15_4_FFD and Mac_802_15_4_RFD to set up the communication between two STM32WB55 Nucleo boards successfully.  But we can't find any code or interface we can use to configure Tx power level.

Thanks in advance

Wenjian at Ingersoll Rand