Carrier Services callback url not being called

[MashaoR]

I've created a carrier service and I can see it from
/admin/api/2021-01/carrier_services.json

Carrier Create Response
{"carrier_service":{"id":54215508130,"name":"Droppa3 Carrier Service","active":true,"service_discovery":true,"carrier_service_type":"api","admin_graphql_api_id":"gid:\/\/shopify\/DeliveryCarrierService\/54215508130","format":"json","callback_url":"https:\/\/537e4ef7e9d0.ngrok.io\/get_rates"}}

But when I add custom shipping the end point is not getting called at all.

In the store settings->Shipping and delivery->Shipping->ManageRate
the Carrier and app rates shows the created carrier service.

I read through documentation and posts but I cannot find anything that might causing the issue

[_JB]

Hey @MashaoR,

It sounds like everything is setup correctly. One thing to double check is make sure you choose a country at checkout where the app is set to return rates. If you're sure you've used a country that is setup to return rates from your app, please provide an example checkout token (the string of letters+numbers in the checkout URL), and we can investigate further. 

[protolabz]

I have double cross checked with Postman API Calling - ok return 200

and also cross checked with direct hitting URL - ok function called

but while placing order its not calling that API or hitting URL

see screenshots and so if any body have solution please reply

Thank in advance