Async callback

async def request(client,URL,json):
    response = await client.post(URL,data=json)
    return response.text


async def task(customers_synt):
    number_of_json = len(customers_synt)
    async with httpx.AsyncClient() as client:
        for x in customers_synt:
            single_dict = x.dict(exclude=generate_exclude_for_ids(model=sdv_models.CustomerSynt))
            single_json = jsonable_encoder(single_dict)
            api_callback_url = "http://192.168.1.112:8111/TDM/ValidationApi-Json-Type-1/"+str(single_json['customer_no'])
            tasks.append[request(client,api_callback_url,single_json)]

        result = await asyncio.gather(*tasks)
        print(result)

@sdv_router.get("/call-validation-api1/",tags=["SDS_DEMO"])
async def call_api1_validation():
    from time import time
    customers_synt = await CustomerSynt.objects.select_all(follow=True).all()
    start = time()
    await task(customers_synt)
    print("time: ", time() - start)
    return {"ok":1}