Add Javascript On Webform Confirmation Page

I am using Webform to generate a form on a page. Wherever this form loads, I need to run some javascript to push some data for Google Analytics 4 on two events (any field is focused, form is submitted regardless of validation results).

For that, I am using this code to load my library that contains all the JS.

function mymodule_form_alter(&$form, \Drupal\Core\Form\FormStateInterface $form_state, $form_id)
{
  if ($form['#id'] == 'myform') {
    $form['#attached']['library'][] = 'mymodule/ga_form';
  }
}

This is all working fine, however, I have a 3rd form state where I need to send the chosen value of a select field to GA. This action should occur when the form is validated/submitted and the confirmation page is loaded. I am using the 'URL with the message option' for the confirmation type on the webform settings. Once the confirmation page is loaded, I have access to the data via the URL parameter like that:

/webform/confirmation?data=[webform_submission:values:type]

The problem is that I can't find a way to load my JS file on the webform confirmation page because since the form is not there anymore, my JS file loaded by the form_alter function is not loaded.