TinyMce v5 - custom image upload

Hello,

I’m new here and looking for some help using TinyMce v5.
I’m using a custom image uploader, with the file_picker_callback and the editor.windowManager.openUrl functions. I succeed opening my own url, but the problem is that the Windows Explorer opens over my own dialog. Of course, I can close it but I would like to know if it is possible to prevent this opening ?

Here is the beginning of my code :

file_picker_callback: function (cb, value, meta) {
        var post_id = document.getElementById('inputid').getAttribute('value');
        var myUrl = "http://localhost/www/Tuto/pilote/medias/index/" + post_id;
        tinymce.activeEditor.windowManager.openUrl({   
            title: 'Gallerie',
            url: myUrl,
            width: 600,
            height: 500,
            resizable: 'yes',
            inline: 'no'
        });
[...]

Thank you for reading me… Hope someone has an idea…