composer require virtualorz/pdfSignature

'providers' => [
    ...
    Virtualorz\PdfSignature\PdfSignatureServiceProvider::class
]

'aliases' => [
    ...
    'PdfSignature' => Virtualorz\PdfSignature\Facades\PdfSignature::class,
]

$pdf_path(string) : real path to the pdf file who want to sign,
$signature_path(string) : real path to the signature image file,
$signature_location(Array) : sign location info array like belo :
                            [
                                [
                                    'page' => 1,
                                    'x' => 15,
                                    'y' => 210
                                ],
                            ]
you can whitch page and x,y location you want to sign,
$download_file_name(string) : the sign result pdf download name