Attachment from external URL

[Asdelon]

Hi!
I want upload some pictures from an array, and attach images to posts in orchid panel.

foreach ($movies as $m) {

        $post = new Post; 
        $post->title =  $m['title'];
        $post->description =  $m['desc'];
        $post->save();

	 foreach ($m['img'] as $g) {			 
		$post->attachment()->syncWithoutDetaching($g);
          }
}

I try
`

		$file = new File(file_get_contents($g);

		$attachment = $file->load();		 

			$post->attachment()->syncWithoutDetaching(
				$attachment
			);

`

and $post->attachment()->syncWithoutDetaching( file_get_contents($attachment) );

But I got error like "Argument 1 passed to Orchid\Attachment\File::__construct() must be an instance of Illuminate\Http\UploadedFile, string given, called in"

But I don't know how to get int from a picture, I want attach for Post model.
Thanks if someone can help me.