I use Apple watch and do not have to enter the data manually in Training Peaks (TP), it uploads automatically for me. I pick an equivalent workout on my Apple Watch (run, hike, etc.) and do the workout. When I’m done I have to place the watch on the charging station and then it will sync with the TP app on my phone. Then I will generally go to my desktop and open TP there as I find it easier to navigate but you can also do it on your phone if you want. Sometimes the workout will automatically pair with the scheduled workout and you are good to go. Sometimes it will pull up as a separate workout but then you drag and drop that workout onto the scheduled workout and then it will ask you if you want to pair them and you reply yes. Once it uploads to TP you can see a map of where you ran, your heart rate over the workout, your TSS score and other important data that you may not get by entering manually.
There are instructions somewhere in TP on syncing with Apple Watch, I don’t remember where.
Good luck and happy training!