First, ensure Windows Store is your target platform in Build Settings. That's what it's called when we're building for UWP:
- In Unity, navigate to File | Build Settings and examine the Platform pane.
- If Windows Store is not presently selected, select it now and press Switch Platform.
On the right-hand side of the dialog are options for the Windows Store platform. Choose the following:
- SDK: Universal 10
- UWP Build Type: D3D
- Unity C# Projects (check this box)