Hi Saadia,
It depends on the watch and the corresponding app you use. I use Garmin and its app automatically picks up sleep and other metrics like stress scores, etc. onto TrainingPeaks, provided you consent to doing so. This is TP’s one of the latest updates.
Other watches and platform – You may or may not manually need to record by adding in the calendar (press + in a day view).
It’s fun to analyze data for optimal performance. In my case, it often leads to more questions, ahaha. Happy crunching!
Yuri