We are currently investigating why some players are not able to make any purchases in the game when playing via the Windows app.
Please note that this issue is only on Windows app and when purchasing via Microsoft Store.
This issue may give you various error messages or just a blank white pop up in the game.
We are looking into this issue and hopefully will have found a solution for it soon.
Meanwhile, please try this workaround which should help until the issue is fixed:
-Open Microsoft Store
-Locate your Account Settings in the top right corner of the screen
-Select App Settings
-Turn on the āPurchase sign-in' feature
-Go back to the game and try making a purchase once again
Thank you for your patience!