BUTTONS_][_CUSTOM_LAYER_]'
    })

    // Define popup buttons.
    Object.assign(FroalaEditor.DEFAULTS, {
      popupButtons: ['popupClose', '|', 'popupButton1', 'popupButton2'],
    })

    // The custom popup is defined inside a plugin (new or existing).
    FroalaEditor.PLUGINS.customPlugin = function (editor) {
      const $ = editor.$
      // Create custom popup.
      function initPopup() {
        // Load popup template.
        var template = FroalaEditor.POPUP_TEMPLATES.customPopup
        if (ty