Your PC was recently updated, but wasn't restarted. You might see an app from Microsoft Store available on your PC, but not on another PC, or your Xbox. Microsoft Store automatically hides or blocks the purchase button on apps that are incompatible with your device. The app isn't compatible with your device. In addition, some apps and games aren't available in Microsoft Store, but can be downloaded from the publisher's site directly. The app is no longer available. When an app is removed from Microsoft Store, it takes a little time for the app description page to get removed. Parents can use family settings to make sure that their child can't view or install apps that are inappropriate for their age. Check that you're signed in with the correct account. Microsoft family settings might be hiding apps. If you bought an app in one country or region and then you moved to another one, the apps you had might disappear. An app available in France might not be available in Germany. The app isn't available in your country or region.
If you still cannot see the app you want, it may be because: Open the Store app and search for your app or game. Note: A blank command prompt window will open, and after about ten seconds the window will close and Microsoft Store will open automatically.