I tried to add this to one of the closed posts on this topic, but that is not allowed.
Just received my new card and was unsuccessful in adding it to Quicken. Found several posts saying it doesn't work. The chatbot on the Virgin Red website also said: "nope, not supported".
However, I noticed that when I logged into the virgenredrewardscard.syf.com website, my Verizon Visa Card (also issued by Synchrony Bank) was also accessible on this website. So I decided to add the Virgin Red card using the link to the Verizon Visa card and — voila — both my Verizon Card and my brand new Virgin Red MasterCard showed up. I added the new card, and all the Google Pay transactions I made while waiting for the card to show up successfully downloaded. So I guess the story is that if you have another Synchrony Bank card, you can use that card to get both. Otherwise, it seems you're out of luck.
P.S. I'm on Quicken Classic for Windows R68.31
[Edited - Readability]