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>

   <form class="">
     <div class="form-row align-items-center config-item" data-key="username">
       <div class="col-sm-5 my-1">
         <span>Bot username (optional)</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="">
       </div>
       <div class="col-auto my-1">
         <button type="submit" class="btn btn-primary">update</button>
       </div>
     </div>
   </form>

   <form class="">
     <div class="form-row align-items-center config-item" data-key="directory">
       <div class="col-sm-5 my-1">
         <span>Directory to watch</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="/...">
       </div>
       <div class="col-auto my-1">
         <button type="submit" class="btn btn-primary">update</button>
       </div>
     </div>
   </form>

   <form class="">
     <div class="form-row align-items-center config-item" data-key="watch">
       <div class="col-sm-5 my-1">
         <span>Period between filesystem checks</span>
       </div>
       <div class="col-sm-4 my-1">
         <label class="sr-only" for="inlineFormInputName">Seconds</label>
         <input type="text" class="form-control rest-field" placeholder="/...">
       </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() {
    let el = $(this);
    let key = el.data('key');

    $.ajax({ method: 'get', url: '/rest/config/'+key})
     .done(function(data) {
       $(".config-item[data-key='"+key+"']").find('.rest-field').val(data.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) {
       if (d.Success) {
         alert('Updated config');
       } else {
         alert("Error: " + d.Error);
       }
     });

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