如何在Laravel中访问URL以呈现页面

Question

I want to display chart image to PDF with dompdf. So I'm create page for render chart, after page render it will be send post to save image. It works when I'm visit URL page in browser it save image in storage. My problem is how to call URL to render page without through browser ?

I was tried with file_get_contents method but it required AUTH so chart image not save in storage. This is method generate data for PDF.

public function generatedPdf($id_siswa){
    //Provide image chart for pdf
    file_get_contents('http://siswaku/chart/'+$id_siswa); //this is not work to save image in storage

    //Provide data for pdf
    $kompetensi = Kompetensi::join('bidang_kompetensi', function($join){
        $join->on('kompetensi.id_bidang','=','bidang_kompetensi.id')
        ->select('nama_bidang');
    })
    ->where('id_siswa', $id_siswa)
    ->where('active', 1)
    ->get()
    ->groupBy('nama_bidang');

    return ['kompetensi' => $kompetensi];
}

My Expect before render PDF, image is available in storage