Sleep app Apple watch

Hi, I’ve purchased an Apple Watch series 3 and I want to simply look at the hours I’ve slept & deep sleep hours every morning on the watch.

I don’t want to set up bedtime etc just a simple look at those, I deleted the sleep app a long time ago (when using another brand of watch) now I can’t find it on App Store on my phone or watch, it only finds third party sleep apps, can someone advise how I find the app please and view this simple date quickly on my watch?. Thanks