I notice that everytime I change Country, State/Province in checkout page, it reloads the Shipping Methods section. Depending on the country/state, it would be 1 or 2 shipping methods.
If I choose UK, there is only 1 shipping method
If I choose US; there is 2 shipping methods
I wonder how it can listen to the input changes and which function in checkout module updates shipping methods. Could you guys show me?