How to pass custom variable from module to jQuery in Drupal 9?

Im the Wallclock module, I have the following Javascript library defined in wallclock.libraries.yml:

digital:
  css:
    component:
      css/wallclock.css: {}
  js:
    js/digital.js: { weight: -1 }
  dependencies:
     - core/jquery
     - core/jquery.once
     - core/drupal
     - core/drupalSettings

The file js/digital.js contains:

(function ($) {
  'use strict';
  Drupal.behaviors.awesome = {
    attach: function (context, settings) {
      function startTime() {
        var today = new Date();
        var hr = today.getHours();
        var min = today.getMinutes();
        var sec = today.getSeconds();
        min = checkTime(min);
        sec = checkTime(sec);
        jQuery('#digital #clock').html(hr + ' : ' + min);
        var pod = ??????;   // How to I pass the custom variable from the module (PHP) to Javascript?
        jQuery('#digital #pod').html(pod);
        setTimeout(function () { startTime(); }, 500);
      }
      function checkTime(i) {
        if (i < 10) {
          i = '0' + i;
        }
        return i;
      }
      startTime();
    }
  };
}(jQuery));

The library is attached to a twig template as follows:

<div id="div"></div>
{{ attach_library('wallclock/digital') }}

My problem is, how do I pass the custom variable "pod" from the module (PHP) to Javascript. The point where I want this to happen is marked with "??????" in the Javascript.