SIK Radio, power level 500mW setting

Just purchased from UMT shop a 500mW 3DR Telemetry Kit V2 (433MHz)
All is good, updated firmware in Mission Planner on both, set personal id on both. :+1:
However maximum power level number that is listed is 20, equating to 100mW, how can I set it to take advantage of the 500mW capability of these radios?
Thank you
Steve :slightly_smiling_face: