How to call API requests to data in 3rd party checkout page
Hello, in my store I have 2 options for checkout one with default Shopify checkout and another one is express checkout (3rd party). In default Shopify checkout I am calling an API to get the shipping details and but on 3rd party checkout page, I am unable to call this API. Can you guide me on how can i pass the shipping charges to 3rd party checkout page?
3rd party URL: https://shop.app/checkout/123456789/shoppay_login
Default checkout: https://www.mystore.com/123456789/checkouts/?step=contact_information&
Please help me on this.