No X1 or Flex box, how do I manage Peacock?

I activated the Peacock Premium Diamond Reward and now https://www.peacocktv.com/account/plans says "Your Plan: Peacock Premium". But it also says "Manage on Xfinity / Billed by Xfinity".  Clicking the Manage link takes me to http://www.xfinity.com/ which prompts me to log in. Once logged in I can find nothing related to my Peacock service.

https://www.xfinity.com/support/articles/peacock-manage-subscription tells me how to manage Peacock using an X1 or Flex box, but I have neither. I use a Tivo for viewing Comcast TV channels and a Roku device for On Demand and Peacock. 

Is Comcast actually going to require customers to get an X1 or Flex box in order to manage their Peacock service? Why is there nothing in the Account pages about Peacock for customers with 3rd party equipment? Peacock's help pages contain all sorts of information for non-Comcast customers, but next to nothing for Comcast customers. Why?

It's hypothetical for now since I'm not planning to make any changes, but if I do decide to make a change, how do I manage my Peacock service???

ETA: The Xfinity Assistant and the Xfinity app were of no help.

Please be aware that there are 2 kinds of responses in this Forum: Replies and Comments. When you Comment on a post by scrolling down to "Comment on this post here...", I am notified of your response. But if you select Reply, I am NOT notified and may not be aware of your response.