I have already seen how to get sensor data and implemented steps count and Heart rate measurement in my app.
Could you tell me which sensor is providing data for Spo2 ?.
is there any way to get Pulse also on watch 3?.
List of supported sensors on my watch 3 
ACCELERATION
GRAVITY
LINEAR_ACCELERATION
GYROSCOPE
LIGHT
PRESSURE
GYROSCOPE_UNCALIBRATED
GYROSCOPE_ROTATION_VECTOR
HRM_RAW