CKEditor won't show the iFrame icon in toolbar

I'm using CkEditor in a Laravel 5 project.

In the config.js under bower_component/ckeditor/ I used the following code:

CKEDITOR.editorConfig = function (config) {
    // Define changes to default configuration here.
    // For complete reference see:
    // http://docs.ckeditor.com/#!/api/CKEDITOR.config

    // The toolbar groups arrangement, optimized for two toolbar rows.
    config.toolbarGroups = [
        {name: 'clipboard', groups: ['clipboard', 'undo']},
        {name: 'editing', groups: ['find', 'selection', 'spellchecker']},
        {name: 'links'},
        {name: 'insert'},
        {name: 'forms'},
        {name: 'tools'},
        {name: 'document', groups: ['mode', 'document', 'doctools']},
        {name: 'others'},
        '/',
        {name: 'basicstyles', groups: ['basicstyles', 'cleanup']},
        {name: 'paragraph', groups: ['list', 'indent', 'blocks', 'align', 'bidi']},
        {name: 'styles'},
        {name: 'colors'},
        {name: 'about'}
    ];

    // Remove some buttons provided by the standard plugins, which are
    // not needed in the Standard(s) toolbar.
    config.removeButtons = 'Underline,Subscript,Superscript';

    // Set the most common block elements.
    config.format_tags = 'p;h1;h2;h3;pre';

    // Simplify the dialog windows.
    config.removeDialogTabs = 'image:advanced;link:advanced';

    config.FormatOutput = false;

    config.allowedContent = true;
};

Also, in the css in the related page, I used the below code:

$(function () {

    CKEDITOR.replace('editor2', {
        allowedContent: true,
    });
});

In the HTML, I used the following code:

<textarea name="content" rows="10" cols="80" id="editor2"></textarea>

In the plugins folder under the bower_component/ckeditor/plugins, I see the "iframe" folder is exist. However, I can't see the iframe icon in the ckeditot toolbar. I configured "allowedContent" as true as mentioned above. Here is the screen grab:

What is the issue?

via Chebli Mohamed