Cardio fitness

Same issue, with iPhone 11, and watch series 6, all on the latest iOS. I have had the watch for two weeks. I have done 2 weeks worth of Outdoor Walks and Fitness+ workouts. All Notifications are On. But still have no way to set up Cardio Fitness function. And it still has no data, or a way to add my Apple Watch as a Data Source. How long does it take?

It can take at least 24 hours wearing your Apple Watch, followed by several workouts and passive measurements with your Apple Watch before you receive an initial estimate.