discord-auto-upload/data/config.html

 <main role="main" class="inner DAU">
   <h1 class="DAU-heading">Config</h1>
   <p class="lead">Discord-auto-upload configuration</p>

   <form class="">
     <div class="form-row align-items-center config-item" data-key="webhook">
       <div class="col-sm-5 my-1">
         <span>Discord WebHook URL</span>
       </div>
       <div class="col-sm-4 my-1">
         <label class="sr-only" for="inlineFormInputName">Name</label>
         <input type="text" class="form-control rest-field" placeholder="https://....">
       </div>
       <div class="col-auto my-1">
         <button type="submit" class="btn btn-primary">update</button>
       </div>
     </div>
   </form>

   <p class="lead">
     <a href="#" class="btn btn-lg btn-secondary">Learn more</a>
   </p>
 </main>


<script>
$(document).ready(function() {
  // populate each field
  $('.config-item').each(function() {
    el = $(this);
    $.get('/rest/config/'+el.data('key'))
     .done(function(d) {
       el.find('.rest-field').val(d.Value);
     });
  });

  // respond to button clicks to update
  $('.config-item button').on('click', function(e,f) {
    key = $(this).parents('.config-item').data('key');
    val = $(this).parents('.config-item').find('.rest-field').val();
    $.post('/rest/config/'+key, { value: val })
     .done(function(d) {
       alert('Updated config');
     });

    return false;
  });
});
</script>