trying to send get value to modal - php

Question

I'm trying to send the get variable from a anchor href to modal. but I cant seem to get the variable $_GET['edit2']. when I try to echo the variable it echo null which is obtain from the else statement. Thank you in advance
Part 1 : used to check if the get variable have been submitted or not.
if(isset($_GET['edit2'])){
$_SESSION['reply_id'] = $_GET['edit2'];
$reply_id = $_SESSION['reply_id'];
}
else{
$reply_id = "null";
}
Part 2 : the anchor href
<a href='?edit2=". $row2['reply_id'] ."' data-toggle='modal' data-target='#myModal'><small>edit</small></a>
part 3 : the modal form
<div class='modal fade' id='myModal' role='dialog'>
<div class='modal-dialog'>
<!-- Modal content-->
<div class='modal-content row'>
<div class='col-12'>
<div class='modal-header'>
<h5 class='modal-title'>Edit Reply</h5>
<button type='button' class='close' data-dismiss='modal'>×</button>
</div>
<div class='modal-body'>
<form id='r_edit_form' method='post'>
<div class='row'>
<label class='col-12'>Reply :</label>
</div>
<div class='row'>
<textarea class='col-12' form='r_edit_form' name='description' rows='4'>". $reply_id ."</textarea>
</div>
<div class='row'>
<input class='col-12 btn btn-dark' type='submit' name='edit_reply'>
</div>
</form>
</div>
<div class='modal-footer'>
<button type='button' class='btn btn-default' data-dismiss='modal'>Close</button>
</div>
</div>
</div>
</div>
</div>