The easiest way I have found to see the IP address for a device on a Windows based computer (up to Win11, which I don't use) is to click on the Windows icon (up to and including Win7) or go to the list in Win10 and click on 'Computer', then look for the device you want to find. I call my MusicCast 'Living Room', so if I left click on it, that opens to the normal screen but right click results in a list that includes 'Properties'- that's where the IP address will show. I sometimes need to find that because my router changes the IP Address occasionally- I need to set the YAmaha to static, but will have to refer to the manual because, for some reason, all of the details are correct, but it won't let me finish. That would prevent me needing to change the IP address when I choose that in my bookmark bar.
You should be able to find the IP address for your AVR in the same way- the gui on a computer is great for setup, use and troubleshooting. The images for a Denon AVR here only show the buttons, not the actual appearance of the gui- the backgroaund is black.
I'll post what I find.