Autofill submit button

<span>Required:</span> <input required=required type="text"> <br>
<span>Required:</span> <input required=required type="text"> <br>
<span>Required:</span> <input required=required type="text"> <br>
<span>Required:</span> <input required=required type="text"> <br>
<div>
  <button>Send</button>
</div>

Test here