use PDF::API2;
my $file = shift; #receive input file as param
my $pdf = PDF::API2->open($file);
my $page = $pdf->openpage(1); #open the first page
my $font = $pdf->corefont('Helvetica-Bold');
my $text = $page->text();
$text->font($font,10); #10-point font size
$text->translate(15,770); #top left corner.. 0,0 origin starts in the bottom left corner
$text->text('blah blah sample text');
$pdf->saveas($file);