Laravel with spatie/pdf-to-text 'could not find pdf book.pdf'

I'm trying to use package spatie/pdf-to-text to convert pdf to text in my laravel project. Pdf located in public path: pdf/file.pdf But I always get this error:

Spatie \ PdfToText \ Exceptions \ PdfNotFound could not find pdf book.pdf

$text = (new Pdf(public_path('pdf/file')))->setPdf('book.pdf')->text();

return $text;

What do I'm doing wrong?

via Chebli Mohamed