I would like to launch a Modal, i used the code from the documentation for both the MDBv2 and MDBv3. an example i tried without the "-mdb-" tag and also with it. But it doesn't display the modal.

here is my code

Launch demo modal

  <div class="modal-body">
    ...
  </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>