Originally Posted by
NickPorter Apps & notifications > App info > Amazon > App Notifications > Notifications 'Make Sound' > Sound.
It took me a minute to find per-app notification settings. But it's there.
(Pixel - Android 8.1)
Slightly off topic, but one of the cooler Oreo shortcuts is the <long press on app> "i" that gets you right to the app settings without going through the normal settings and finding your app.
In this case you could just long press your Amazon app and click the little "i" at the top and go to notifications. Saves a bit of time and a step or 2 ..