Javascript POST an PHP (Anfänger)

[BastiBln]

Funktioniert leider auch nicht. Hier mal etwas mehr Code:

Code:

<div class="form-block w-form">
  <input type="number" onchange="ingredsCalc()" class="text-field w-input" max="25" maxlength="256" name="Persons" step="1" value="<?php if(isset($_POST['Persons'])){echo $_POST['Persons'];}else{echo $load_recipe['persons'];}?>" min="1" id="Persons">
  <input type="text" id="recipe_public" name="recipe_public" value="<?php echo $recipe_id?>" hidden>
    <div class="block-title">Persons:</div>
    <script>
    function ingredsCalc(){
      var persons = $('#Persons').val();
      $.ajax({
         type: "POST",
         url: "recipe_view.php",
         data: {Persons: persons},
         cache: false,
         success: function(response){

         }
      });
    }
    </script>
    </div>
    <div class="block-title">Ingredients:</div>
    <div class="ingredients-text-block w-richtext">
    <?php echo var_dump($_POST['Persons']); ?>
  </div>
</div>

Einen Post kann ich in der Konsole sehen, aber die Variable bleibt leer.