JSFiddle - React, Tailwind, and code Playground

HTML

<div class="vignette">
    <div class="gris"></div>
     
    <form method="post" action="news.php?action=insert" id="add_articles">
                               
        <p>                                  
            <label for="title">Titre</label> : <input type="text" name="title" id="title" />
             
            <textarea class="ckeditor" name="content" id="content"></textarea>
                                     
            
        </p>
        <input type="button" value="Ajouter" id="add_chap" name="add_chap" />
       
    </form>       
</div>

CSS

textarea, input[type="button"]
{
    display: block;
}

JavaScript

jQuery("#add_chap").click(function(){
    $("#add_articles p").append("<textarea name='chapitre[]'></textarea>");
});