Buying Ancient Coins on Steam while owning a game from Microsoft Store

Hi, I own this awesome and unique game of Sea of Thieves since September 2019 which I bought on Microsoft Store for my PC, I've just added 90 euros into my Steam Wallet and realized that it was a bit too much. As the game is now available on Steam and offers the option of linking my Microsoft account to my Steam account, I was wondering if it could be possible to buy ancient coins on Steam and use them in my Sea of Thieves which was bought on a different platform which in my case is on Microsoft Store. If you would happen to know the answer or to have tried the same thing, please let me know if it is possible or not.