This switch is located at Channel>Channel Settings>Walmart Settings tab.
If you want to set ship price updates, you have two options: By Shipping Override and By Shipping Template.
By Shipping Override
If you select “By Shipping Override”, the shipping prices of products on your Walmart channel will be updated according to the shipping template you have overridden.
By Shipping Template
Before selecting this option you must have created and populated a Shipping Template.
If you select “By Shipping Template”, the product shipping prices will be updated by default shipping templates assigned to the products on SA.
To set this feature, you also need to select a “Ship Node” from the dropdown menu. Ship Nodes are the fulfillment centers you have created for Walmart.
IMPORTANT NOTE: These settings will be applied to all products using shipping templates on channel level.