This code adds a back button to the site header when our site is viewed in the MobiLoud app. When testing locally, everything works fine, but in the app, the `window.history.back()` method doesn't seem to work. I tested whether the event listener is being added in the app, and it is.

app_back_button.js

(function (Drupal, FontAwesome) {

  'use strict';

  Drupal.behaviors.appBackButton = {
    attach: function (context) {

      const mobileNavIconWrapper = document.getElementById('nav-mobile-show');
      const isApp = navigator.userAgent.toLowerCase().includes('canvas');
      if (!isApp) {
        if (mobileNavIconWrapper) {
          mobileNavIconWrapper.style.visibility = 'visible';
        }
        return;
      }

      const isFront = document.body.classList.contains('front');
      if (isFront) {
        return;
      }

      const backIcon = FontAwesome.icon({
        prefix: 'far',
        iconName: 'chevron-left'
      }).node[0];

      // Replace the mobile menu icon with a back button in the mobile app.
      if (mobileNavIconWrapper) {
        const backButtonWrapper = document.createElement('div');
        backButtonWrapper.classList.add('mobile-back-button-wrapper');
        const backButton = document.createElement('button');
        backButton.classList.add('mobile-back-button');
        backButton.prepend(backIcon);
        backButton.setAttribute('aria-label', 'Back to previous page');
        backButton.setAttribute('title', 'Back to previous page');
        backButton.addEventListener('click', function () {
          window.history.back();
        });
        backButtonWrapper.appendChild(backButton);
        mobileNavIconWrapper.parentNode.replaceChild(backButtonWrapper, mobileNavIconWrapper);
      }
    }
  };


})(Drupal, FontAwesome);