<div class="row">
    <div class="col-md-12">
        <label>Email</label>
        <input type="email" class="form-control" name="email" id="email" value="<?php echo isset($email)?$email:""; ?>" required/>
    </div>
</div>
<input hidden="" name="id" value="<?php echo $id; ?>"/>
<?php
$pdf_path=base_url(uploads_path."/donation_receipt/"."donation_receipt_".$id.".pdf");
?>
<div class="row mt-2">
    <div class="col-md-12">
        <label>Receipt</label>
        <iframe width="100%" height="350px;" src="<?php echo $pdf_path; ?>" title="description"></iframe>
    </div>
</div>