VO2 i not the same thing as VO2 max.
VO2 is the level of oxygen your body can consume and convert to energy at a given time, which VO2 max is the maximum amount of oxygen that your body can consume and convert to energy.
In other words, your VO2 varies throughout the day. Your VO2 could be 20 mL/kg/min while you’re sitting at your desk, and it could be 30 mL/kg/min later when you’re walking up a flight of stairs. VO2 max is the highest number that can be achieved during maximal exercise exertion.