self.fetch_task = fetch! {
    LoginCredentials { // the request struct from the core
        username: "username".to_owned(),
        password: "password".to_owned(),
    } => API_URL_LOGIN_CREDENTIALS, // reuse the global API constants
    self.component_link, // the current component
    Message::Fetch, // the message type for the component
    || {}, // Do something on success
    || {}, // Do something on error
};