Hello LivingInOhio,
Thanks for connecting with Apple Support Communities. We understand that you're not receiving notifications for the Amazon app.
You've completed some great troubleshooting steps so far.
We'd like to provide you with some additional steps that may help resolve the issue:
• Be sure that the app is running in the background and not closed. Here's how to check: Close an app on your iPhone or iPod touch
• Restart your iPhone
1. Press and hold the side button until the power-off slider appears.

2. Drag the slider, then wait 30 seconds for your device to turn off. If your device is frozen or
unresponsive, force restart your device.
3. To turn your device back on, press and hold the side button until you see the Apple logo.
• Delete the app. When you do this, you might lose data that was stored in the app.
Then redownload the app. Then check to see if the problem with the app is fixed.
Click here for more details: If an app on your iPhone or iPad stops responding, closes unexpectedly, or won’t open
Let us know if the helps.
Best wishes!