Can Apple Watch, measure vo2max?

Hi,

Yes it does, not completely accurately as it's just an estimation. If you look in the Health app after a 20 min plus walk or run you should see a value.

“Values stored from Apple Watch represent a predicted VO2 Max, and are captured during intense Outdoor Walk or moderate to intense Outdoor Run sessions in the Workout app that are at least 20 minutes in length and maintain a persistent heart rate throughout the workout session.”