How to show Specific URL of WordPress on Any one Specific IP only?

A simple way of doing this would be to use template_redirect and return a 404 status code if the clients ip address does not match the desired one:

add_action('template_redirect', function () {
  /** @var \WP_Query $wp_query */
  global $wp_query;

  if ($wp_query->get_queried_object()->post_name === 'hello-world') {
    $address = $_SERVER['HTTP_X_FORWARDED_FOR'] ?? $_SERVER['REMOTE_ADDR'];
    if ($address !== '172.20.0.1') {
      // Return a 404 page.
      $wp_query->set_404();
      status_header(404);
    }
  }
});

The above will return a 404 http response if a user with another ip address then 172.20.0.1 try to visit a page with the name hello-world. You will need to modify the above code to match the name of your page as well as the ip address that you would like to give access to.

You might also return a 401 (Unauthorized) using:

status_header(401);

I think you still might be able to access to page using a query string e.g. /?page=1, but you could fix this by doing this instead:

if ($wp_query->post->post_name === 'hello-world') {
  // ...
}