Datasheet mentions indeed analog signal output, but reading a bit further it says:
Vout (0.4~2V,custom made)
which to me implies that not all sensors have this option.
Anyway, the sensor also has UART output, and all of them seem to have that (no "custom made" mark there) that's a lot easier to read with an Arduino than a PWM signal. I'd go for that, then if you must have an analog voltage output indeed PWM output + low pass filter. That should be able to provide a few mA of signal.