Ckeditor 5文件上传适配器错误

I'm using ckeditor classic 5, and i'm trying to upload images in it. I downloaded php lib Ckfinder3 php connector, set config.

When i'm trying to load image i have a massage: Cannot upload file *filename*.

Interesting moment, that they are fisically loaded on server: i can view it in directory, that set in my config file and this files are correct:

/var/www/projectfiles/downloadfiles/

The next step i'm check permission and groups: it's www-data 0777.

What can be a reason? Can you give some advice or solution?

Thanks!

UPD: init function

ClassicEditor
            .create( document.querySelector( '#material_preview' ), {
                ckfinder: {
                    uploadUrl: '/ckfinder/connector/?command=QuickUpload&type=Images'
                }

            } )
            .catch( error => {
                console.error( error );
            } );

php config:

$config['authentication'] = function () {
    return true;
};

$config['backends']['default'] = array(
    'name'         => 'default',
    'adapter'      => 'local',
    'baseUrl'      => 'http://files.project.com/downloadfiles/',
    'root'         => '/var/www/projectfiles/downloadfiles/',
    'chmodFiles'   => 0777,
    'chmodFolders' => 0777,
    'filesystemEncoding' => 'UTF-8'
);

Finally i got it!

The connector path is valid. The problem was in cache folder's permisson in laravel. Be glad if it helps you.

The connector path looks invalid. For PHP it should be something like: '/ckfinder/core/connector/php/connector.php?command=QuickUpload&type=Files' Please have a look at CKEditor integration examples in CKFinder demo: https://ckeditor.com/docs/ckfinder/demo/ckfinder3/samples/ckeditor.html