Use of FPDF library in CI4

I want use fpdf in my project CI4.. how i can do this step by step? How include it as thirdparty?!

<?php namespace App\Controllers\Purchase;

namespace App\ThirdParty\fpdf;

use CodeIgniter\Controller;

use FPDF;
?>
and how build the controller to call fpdf methods?!

$pdf = new PDF();
$pdf->AddPage();
thanks