Not if you can't find it. But if you look
here, you'll see a few Youtube apps by Google, so you don't have to sideload it. And if an app comes as an .apk file, all you do is tap the apk file, you don't have to sideload anything. (Sideload is an old term used for installing zip packages using adb [since JellyBean] - we just
install apk files.) (Unless you want to go
way back, to when AT&T wouldn't allow installation from Amazon, so you had to download the apk file, then tap it. That was also called sideloading - back around 2009.)