modal.php

<?php echo $_SERVER['HTTP-HOST'] ?>
<button type="button" class="btn btn-primary" data-toggle="modal" data-target="#exampleModalCenter">Launch demo modal</button>
<div class="modal fade" id="exampleModalCenter" tabindex="-1" role="dialog" aria-labelledby="exampleModalCenterTitle" aria-hidden="true"><div class="modal-dialog modal-dialog-centered" role="document"><div class="modal-content"><div class="modal-header"><h5 class="modal-title" id="exampleModalLongTitle">Modal title</h5><button type="button" class="close" data-dismiss="modal" aria-label="Close"><span aria-hidden="true">&times;</span></button></div><div class="modal-body"><?php if ($_SERVER['HTTP-HOST'] == "testnico.local") {echo "texte modal testnico";}else {echo "texte modal wordpress";} ?></div><div class="modal-footer"><button type="button" class="btn btn-secondary" data-dismiss="modal">Close</button><button type="button" class="btn btn-primary">Save changes</button></div></div></div></div>