A new report that will provide visibility into item-level overrides set through Bulk Item Override API or Return Rules Spec in Seller Center is now available through API. You can download this report for information on item overrides set for individual items in your catalog.
Return overrides included are Keep It, Return Restricted, Restriction Reason, Return Center (Alias). Report will only include SKUs that have an override. SKUs without any override will not be included. If you do not have overrides set for any SKUs, the report will be generated with a message "No Item Overrides Found".
Return Item Overrides Report URL : https://marketplace.walmartapis.com/v3/getReport?type=returnOverrides
For more details, API documentation can be referred here.