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Is there any doc that can help me in testing GSP feature in sandbox environment ?
Please refer to the attached documents for understanding and testing the Global Shipping Program in sandbox environment.
FYI, a new Flag, IsMultiLegShipping has been added to the post-transaction API’s. The flag will indicate if GlobalShipping Program was used for the transaction.
NOTE : GetItem(in sandbox) will not return any node indicating listing is GSP enabled or not. You need to complete checkout and only the post transaction apis(like GetItemTransactions api) will return GSP related node in sandbox.
Please keep in mind that this tag is introduced in version 793, so you should make sure that the version/compatibilty level is set to 793 or higher.