Setting up multiple locations does have to be done in Shopify and is easy to do. The full details on how to accomplish this will be outlined below:

Using split fulfillment, Thrive will directly mirror what happens in Shopify to ensure accurate deductions/restocks across your fulfilling locations. For example, if you change the fulfillment location for an order in Shopify, Thrive will automatically mirror the inventory adjustment on the Shopify side.

For Thrive to ensure proper deductions or restocks, we recommend all involved Shopify channels should be mapped in Thrive. Otherwise, if an order is fulfilled by or restocked to an unmapped location, we won't be able to pinpoint where the deduction/restock is happening, which can cause counts to be incorrect.

The rules for which locations are used to fulfill orders and in what priority can be set up on your Shopify store. Here is more information about ensuring your Order Management is set up correctly in Shopify.