Yii2 Flysystem - Azure文件系统错误

I am using https://github.com/creocoder/yii2-flysystem in a Yii2 application. I have set the following in the config

    'azureFs' => [
        'class' => 'creocoder\flysystem\AzureFilesystem',
        'accountName' => 'mystorageacctname',
        'accountKey' => 'its-really-long-alphanumeric-special-char-key',
        'container' => 'pathforstorage',
    ],

And in my controller, I am calling the following

    if($file = UploadedFile::getInstanceByName('uploaddocs'))
    {
        $stream = fopen($file->tempName, 'r+');
        Yii::$app->azureFs->writeStream($fpath. $fname, $stream);
    }

However, I get this error:

InvalidArgumentException Provided URL is invalid.

I have installed all dependencies as well. I am not sure where I am going wrong.