How to Edit Existing pdf using fpdf Library in PHP

Below is my code:

require_once
'../includes/fpdf/fpdf.php';

require_once
'../includes/fpdf/fpdi.php';

$pdf
= new FPDI();

$pageCount
= $pdf->setSourceFile("contractFinalTrans.pdf");

$tplIdx
= $pdf->importPage(1);

$pdf->addPage();

$pdf->useTemplate($tplIdx,
10, 10, 200);

//set
position in pdf document

//
now write some text above the imported page

//$pdf->SetFont('Arial');

$pdf->SetFontSize(10);

$pdf->SetTextColor(255,0,0);

$pdf->SetXY(50,
50);

$pdf->Write(0,"page 1");///print this output

$pdf->SetAutoPageBreak(true,22);

$pdf->addPage();

$tplIdx
= $pdf->importPage(2);

//$pdf->addPage();

$pdf->useTemplate($tplIdx,
10, 10, 200);

//set
position in pdf document

//
now write some text above the imported page

//$pdf->SetFont('Arial');

$pdf->SetFontSize(10);

$pdf->SetTextColor(255,0,0);

$pdf->SetXY(100
, 100);

$pdf->Write(0,"page 2");

$pdf->Output();

Can anyone suggest me how to Edit Existing multiple pdf using fpdf Library in PHP

I have explored manyphp developer forum related to this issue but I am unable to get satisfactory solutions. Hope this forum help me out for the same issue.