doom eternal windows version
Welcome to the community. 
Trainers are only made if there are enough WeModders who play the game from each store. The WeMod software detects how many WeModders own the game and farm which stores. If it is a good number then it’ll eventually appear in the queue, which you can see in the desktop app.
Just to let you know, Windows Store is very unpopular in the gaming community, which is why there are so few Windows Store trainers on the internet when compared to Steam, Epic and Uplay.
More information on how trainers get developed: Game Queue - WeMod Support.