Opening external url on tauri and detecting the page is fully loaded

[fgroupindonesia]

My current main.rs file content is

// Prevents additional console window on Windows in release, DO NOT REMOVE!!
#![allow(unused)] 
#![cfg_attr(not(debug_assertions), windows_subsystem = "windows")]
#[derive(Clone, serde::Serialize)]
struct Payload {
  message: String,
}

use std::fs;
use tauri::Manager;

fn main() {

let custom_js = fs::read_to_string("ads-blocker.js")
        .expect("Failed to read custom.js file");

tauri::Builder::default()
   .setup(|app| {
             let window = app.get_window("main").unwrap();
            
            // Add a listener to detect when the URL has fully loaded
            window.listen("tauri://loaded", move |_event| {
                println!("URL fully loaded!");
                
            });


      Ok(())
    })
    .run(tauri::generate_context!())
    .expect("failed to run app");

}

And for the rest of the tauri.conf.json file was here..

My question is how do i detect the page is fully loaded?
And why the println() didnt come up to the output? Is there anything i missed?

Thanks in advanced.