Using Model Dropbox Methods wiht POST

[chapus]

Im new using this, when I try to create a folder i get the next error:
Not Found
Error: An Internal Error Has Occurred.
Stack Trace
APP/Plugin/Dropbox/Model/Datasource/DropboxSource.php line 172 → DropboxSource->_request(string)

I see when the method needs to be a POST method I dont know how to use it. Can you help me providing some example for this method ?, Im calling the method inside a controller function.

public function dp_mkdir() {
    if ( !empty($this->request->data) && $this->request->isPost() ) {

        $folder = $this->DropboxApi->mkdir( );

        $this->set( compact('folder') );
    }
}