How to stream Amazon Prime Music

How have you configured the sound output for the PC?  In the settings area have you designated the DAC as where you want the sound to be directed, instead of the internal Computer Speakers?  Do you listen to other music from the computer via the usb connection?  If so then you may have to check the setting within Amazon.

Thanks. 
Actually this is going to be my first attempt in streaming via the USB DAC so my questions may appear to be naive.  I currently have a laptop so I guess it has a built-in sound card, but I can try to see if I can direct the audio stream to one of the USB port.  To me, conceptual it is rather simple but I don't know if the PC has the hardware implementation for it.I am just curious?  Could you describe your PC setup for USB?

So based on your suggestion, I did a quick search of "how to direct sound from labtop to usb port".  It turns out to be rather simple.  First I need to purchase a USB DAC.  Plug into one of the laptop USB port.  Go to control panel and select the USB DAC as the default playback device.  At least that should work in theory.Now that the USB DAC is the default device, either streaming through Amazon Prime or anything on the laptop would go to the USB DAC. 

Correct. You may need to install a driver since you are using a PC. The DAC you choose will specify this. In some cases Windows will offer up the appropriate driver.

I’m a bit confused, because your original post seems to imply that you have a DAC that connects to your PC by usb, but one of us seems to be missing something...Anyway, my setup is I have a Mac Air that is connected to the usb input of a Bryston DAC3.  I had to change the sound settings in the Mac to designate the Bryston as the desired output instead of the Computers internal speakers.  It’s been a while since I’ve used a Windows PC but they have something similar in their control panel, and as the last poster mentioned with some DACs Windows Computers need a special driver installed.
  I hope this helps

Bluesound / Node has good Amazon HD playback, I've read. You can integrate an Alexa device into the  Node for voice commands. Amazon doesn't play with mfrs that don't integrate Alexa into their devices. I used to be able to stream Amazon HD from the phone app to my Chromecast Audio puck which is plugged into my DAC/preamp, but Amazon locked that device out. They're control freaks. :(

Stream Amazon Prime Music to play on USB DAC offline? To do that, you might draw support from an Amazon MP3 downloader tool. It assists you to convert songs from Amazon Prime Music to common formats like MP3, AAC, FLAC, WAV, M4A, etc with lossless quality, and then save Amazon songs to the local computer forever. After that, you just need to transfer local Amazon Prime Music songs to your USB for offline playback without limits.

Interesting there are 3 trolls on this post that are all pushing products. Maybe they think nobody notices. Anyone click on any of the 3 users jiang.., filly.., jam.. for their recent activity and these imposters are all hanging together on the same posts and recommending certain apps. And I'd bet their posts are originating in Asia.

If the DAC isn't recognized when you plug it in it's a driver issue.  If it is recognized it need to be selected from the speaker icon on the lower right corner.

I'm streaming Amazon HD from a windows PC as we speak / type.  I did use the appropriate driver provided by the manufacture.