I want a complete contact form, with. html included

#[derive(Debug)]
struct User {
    username: String,
    first_name: String,
    last_name: String,
    age: u8
}

fn main() {
    let mut user = User {
        username: String::from("user"),
        first_name: String::from("first"),
        last_name: String::from("last"),
        age: 0
    };

    user.username = String::from("new_user");

    println!("{:?}", user);
}