Imu temperature calibration

i’m using pixhwack2.And i found the heater of register in imu can’t be used by looking the code.and see some document like : “Pixhawk 2.1 IMU Heater Support”
so i found a document in "Thermal Calibration and Compensation "

but i found the funciton “got_temperature_calibration_command” can’t be called anyway.
The function got_temperature_calibration_command be called by the command whtch sent by QGC,But the Qgc only sent

i fount it.
“Power the board and set the SYS_CAL_* parameters to 1 to enable calibration of the required sensors at the next startup. 1”