mpdf import all pages from another pdf document

In the example the index in "$pdf->ImportPage($i)" is missing.

$pdf->SetImportUse();
$pagecount = $pdf->SetSourceFile([LOCAL_FILEPATH]);
for ($i=1; $i<=($pagecount); $i++) {
    $pdf->AddPage();
    $import_page = $pdf->ImportPage($i);
    $pdf->UseTemplate($import_page);
}

Use page count you get form setting source file in a loop (like below)

$pdf = new mPDF();
$pdf->SetImportUse();
$pagecount = $pdf->SetSourceFile($dashboard_pdf_file);
    for ($i=1; $i<=$pagecount; $i++) {
        $import_page = $pdf->ImportPage();
        $pdf->UseTemplate($import_page);

        if ($i < $pagecount)
            $pdf->AddPage();
    }
$pdf->Output();