Add NavigationLink in NavigationView with destination view class name. See following code:

NavigationLink(destination: <DestinationView>) { 
    // your code
}

See more details here: https://developer.apple.com/tutorials/swiftui/building-lists-and-navigation#set-up-navigation-between-list-and-detail

I hope this will fix your issue.

To fix your issue you need to bind and manage tag with NavigationLink, So create one state inside you view as follow, just add above body.

@State var selection: Int? = nil

Then update your button code as follow to add NavigationLink

NavigationLink(destination: Text("Test"), tag: 1, selection: $selection) {
    Button(action: {
        print("login tapped")
        self.selection = 1
    }) {
        HStack {
            Spacer()
            Text("Login").foregroundColor(Color.white).bold()
            Spacer()
        }
    }
    .accentColor(Color.black)
    .padding()
    .background(Color(UIColor.darkGray))
    .cornerRadius(4.0)
    .padding(Edge.Set.vertical, 20)
}

Meaning is, when selection and NavigationLink tag value will match then navigation will be occurs.

I hope this will help you.