Import file but file get from FTP

[abdrozak20]

I want to import file, but i get file from FTP.
this is my code :
$file_nortels = Storage::disk('ftp_nortel')->get('template-dp.xlsx');
$import = new DPImport();
$import->forEvent($session_id)->import($file_nortels, null, \Maatwebsite\Excel\Excel::XLSX);

But i get error :
touch() expects parameter 1 to be a valid path, string given

please help me.
thanks