TypeError: $(...).parent(...).next(...).fadeToggle is not a function
<p>I am using a Django site.This is a script that I have included inside the body</p>

<pre><code>$(document).ready(function(){
    $(".comment-reply-btn").click(function(event){
        event.preventDefault();
        $(this).parent().next(".comment-reply").fadeToggle();
    })
})
</code></pre>

<p>This is my HTML </p>

<pre><code>&lt;blockquote&gt;
         &lt;p&gt;{{ comment.content }}&lt;/p&gt;
         &lt;footer&gt;by {{ comment.user }} , {{ comment.timestamp | timesince }} ago |
             {% if comment.children.count &gt; 0 %}{{ comment.children.count }} Comment {% endif %}
             {% if comment.children.count &gt; 1 %}s {% endif %} |&lt;a class="comment-reply-btn" href="#"&gt; Reply &lt;/a&gt;&lt;/footer&gt;
         &lt;div class="comment-reply"&gt;
          {% for child_comment in comment.children %}
             &lt;blockquote&gt;
                  &lt;p&gt;&amp;mdash; {{ child_comment.content }}&lt;/p&gt;
                  &lt;footer&gt;by {{ child_comment.user }} , {{ child_comment.timestamp | timesince }}ago&lt;/footer&gt;
                 &lt;br&gt;
             &lt;/blockquote&gt;
            {% endfor %}
             &lt;form method="post" action="."&gt;{% csrf_token %}
                 {{ comment_form | crispy }}
                 &lt;input type="hidden" name="parent_id" value="{{ comment.id }}" &gt;
                 &lt;input type="submit" value="Reply" class="btn btn-inverse" &gt;
             &lt;/form&gt;
         &lt;/div&gt;
&lt;/blockquote&gt;
</code></pre>

<p>These are my scripts(I included two just to be sure):</p>

<pre><code>   &lt;script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.1.0/jquery.js"&gt;&lt;/script&gt;
&lt;script src="https://ajax.googleapis.com/ajax/libs/jquery/3.1.0/jquery.min.js"&gt;&lt;/script&gt;
&lt;script   src="http://code.jquery.com/jquery-3.1.0.slim.min.js"   integrity="sha256-cRpWjoSOw5KcyIOaZNo4i6fZ9tKPhYYb6i5T9RSVJG8="   crossorigin="anonymous"&gt;&lt;/script&gt;
</code></pre>

<p>I am getting this error :</p>

<blockquote>
  <p>TypeError: $(...).parent(...).next(...).fadeToggle is not a function</p>
</blockquote>

<p>I have no idea whatsoever since I copied the code directly from a video</p>