On what computer? Temperature sensors are not standardized on Macs and are completely undocumented. Anyone making a temperature sensor app has to reverse engineer the sensors. If this is a new model Mac then they probably haven’t done the work yet.
Fans in a 16" M1 Pro/Max MBP for example are usually off until the SoC is close to its rated operating temperatures where it would throttle. M2 Pro/Max likely the same.