views.py

@csrf_exempt
def init(request):
    if not request.body:
        return JsonResponse(status=200, data={'message': 'No request body'})
    body = json.loads(bytes(request.body).decode('utf-8'))

    if 'username' not in body:
        return JsonResponse(status=400, data={'message': 'Username is required to join the channel'})

    username = body['username']
    ...