Pass data from JS to Python via Django

I want to send data from python to JS in Django. I successfully see the data in the response in the browser, but JS returns as empty string. What would be the reason?

trying to fetch information;

def XXX(request):
    message_id=request.POST.get('messageid')
    return render(request, 'XX.html')

sender;

    y = json.loads(response.text)
    ts = str(y["file"]["shares"]["public"]["XX"][0]["ts"])
    return render (request, 'problemduyurusucreate.html', {'ts':ts})

JS;

...
var test = "{{ ts }}";
                $.ajax({
                type: "POST",
                url: "{% url 'slack' %}",
                data: { 
                  "messageid": test,
                csrfmiddlewaretoken: '{{ csrf_token }}'
                }  
...

but I am displaying in my browser that I have successfully pulled the data