Special="save" button doesn't work in odoo16 form view

Question

When I add my "save" button and "discard" button as following:

<footer>
  <button string="Save" special="save" class="btn-primary" close="1" />
  <button string="Discard" class="btn-secondary" special="cancel"/>
</footer>

Both buttons dont work and when I click them, nothing happends.