query parameters with question mark and Query types

#[tokio::main]
async fn main() {
    let routes_hello = Router::new().route(
        "/hello", // path
        axum::routing::get(handler_hello),
    );
    let addr = SocketAddr::from(([127, 0, 0, 1], 8080));
    println!("@@@@@ LISTENING ON {}", addr);
    axum::Server::bind(&addr)
        .serve(routes_hello.into_make_service())
        .await
        .unwrap();
}

async fn handler_hello(Query(params): Query<HelloParams>) -> impl IntoResponse {
    println!("@@@@@ {:<12} - {params:?}", "HANDLER");
    let name = params.name.unwrap_or("World".to_string());
    Html(format!("Hello <b>{name}!!!</b>"))
}