How to simulate SAR in CST MWS?

im trying to simulate SAR in CST MWS. i know i should select power loss/SAR in field monitoring to do that. but SAR value still not appearing after simulation. so i did open SAR examples in CST and create my own phantom because only head phantom available in CST and what i want is flat/tank phantom. i created my unique phantom with same materials as in example (shell and fluid). however, after simulation, power loss density is given in W/m3 and SAR will be in W/kg. please help