WidgetView on Xcode 14

The moment I set a SwiftUI View's preview context to WidgetPreviewContext, Xcode shows an error saying

"UnableToFindPreviewHostError: Could not find host for previews

Could not find a host (app, extension, framework) given the open files and active PreviewProvider types. Make sure the open files and PreviewProvider types are target in the active scheme.

sources: , SubManagerWidgetView.swift commonAncestors: SubManager.app graph: target app SubManager.app (#1) translationUnit SubManagerWidgetView.swift (#2) Preview (#3)"

Does anybody know the reason for this?

By the way, my code is:

import SwiftUI
import WidgetKit

struct SubManagerWidgetView: View {
var body: some View {
    Text("Hello, World!")
   }
}

struct SubManagerWidgetView_Previews: PreviewProvider {
static var previews: some View {
    Group {
        SubManagerWidgetView()
            .previewContext(WidgetPreviewContext(family: .systemSmall))
      }
   }
}