Just confirming I have all the steps correct, since it can't be tested in preview, and didn't work for me the first time I tested on Xbox One with Test mode on:
Add WindowsStore plugin
At start of layout > Request store listing
If player selects a purchase-able character:
WindowsStore|X (Invert) Has purchased "Character" > WindowsStore|Prompt to purchase product "Character"
Is that all there is to it? If so, my guess is that even though the Add-ons I created have the "In the Store" status, they really take a little longer before that prompt does anything?
Just making sure there isn't some bigger issue, like that WindowsStore add-ons don't work on Xbox One.
Edit: Or is there any chance that the event work is wrong, like that it has to be simpler, like just a purchase button that immediately prompts the purchase, instead of starting with a check if you already have it or not?
Edit2: Okay, when testing with Test mode off it tells me to Reinstall the app from the Store, because my license needs to be refreshed to make in-app purchases. So thankfully it looks like it will work, anyway. Thanks!