1. Continuous blood oxygen monitoring:
Pair the watch with the app. In the app, go to My Devices > Health monitoring > 24/7 Blood oxygen monitoring,enable it. Put on the watch and it will start to automatically measure your blood oxygen once every 30 min.
2. Manually measure your heart rate:
Put on the watch, and remain still. Press the button to open the function list, and select Blood Oxygen. Tap to enter, and the Watch 3 Pro will start to measure your current blood oxygen.