Cardiofitnes

I have a new Apple Watch 6, iOS 7.3.3 and iPhone 11 latest iOS. I cannot use cardiofitness. I do not see an option to install it and within the health app, it says no resources available. I used it for three weeks, during sport and training.

saturation and heartbeat are available in the health app on my phone health app.

I have reset the calibration of data a week ago, still no change. Does anyone knows what’s going wrong?