Ambient light sensor problem

Hello there! When I developing my app the standard android sdk don’t see the light sensor, when I call him, he return Null. I searched information about this issue and found in stackoverflow
(Android Light Sensor Returns null - Stack Overflow )
so what Samsung phones don’t have a light sensor, it’s really true? But my debugging Samsung Galaxy m21 have a adaptative brightness function. How can I call and get data from light sensor?

thanks Mia, I will try