Some UI elements not appearing on HTML page

[hsharghi]

I used vercel-starter-kit and it worked as expected. Print some HTML text. But as I tried to add some Button and TextField it's not showing up in the rendered HTML page.

import Vercel
import VercelUI

struct App: ExpressHandler {
    static func configure(router: Router) async throws {
        router
            .get("/", IndexPage())
    }
}


struct IndexPage: View {
    
    @Environment(\.request) var req
    @State var name: String = ""
    
    var body: some View {
        VStack {
            TextField("Enter your name", text: $name)
            Button("Click Me!", action: {
                print("clicked")
            })
            Text("Hello, Swift")
                .font(.title)
            
            Text("This is a server rendered SwiftUI website")
                .font(.subheadline)
            
            Text("Your ip address \(req.clientIPAddress)")
        }
    }
}

The output is just text without input field or button

What am I doing wrong?