Convert PDF to Images

I am trying to convert a pdf file to images using imagick and using Laravel.

$pdf_file = Storage::disk('uploads')->url($name);
$image = new imagick();
$image->readImage($pdf_file);
$image->setImageFormat('jpg');
$pages = $image->getNumberImages();

but when I try to execute it I get the following error:

Imagick::readImage not implemented

Does anyone know what is happening?