Add custom font mpdf-laravel - php

Question

I have a problem in adding a custom font to generated pdf .I used mpdf package and I did all the steps the add a custom font .I created a pdf.php in config folder with the code below
<?php
return [
'custom_font_dir' => base_path('resources/fonts/'), // don't forget the trailing slash!
'custom_font_data' => [
'circular-black' => [
'R' => 'CircularStd-Black.otf', // regular font
]
// ...add as many as you want.
]
];
and in my controller
use PDF;
class pdfController extends Controller
{
public function generateResultat($id){
$resultat=some data;
$fileName='Resultat Order-'.$resultat->order->examCodeSession.'.pdf';
$mpdf= new \Mpdf\Mpdf([
'mode' => 'utf-8',
'format' => 'A4',
'margin_left'=>10,
'margin_right'=>10,
'margin_top'=>15,
'margin_bottom'=>20,
'margin_header'=>10,
'margin_footer'=>10,
]);
$html=\View::make('pdf.resultat',[
'resultat'=>$resultat
]);
$html->render();
$mpdf->WriteHTML($html);
$mpdf->Output($fileName,'D');
}
}