Using Third Party CCS

Hello

I’m developing a Shopify Store using Hydrogen.

I’m using some third party CCS apps and currently I’m trying to test freight prices locally

Doing queries to get CarrierServices from the app, the callbackUrl always comes as “null”, and I’m always getting the fallback freight price on the frontend, locally

There is a correct way in order to test the service locally? Or it jus’t works on production deployments?