You can enable the Return option on forward order from Returns Settings.
Go to Settings >> Return Settings.
Here, turn the toggle on “Enable Buyer Return workflow on Tracking Page”.
From the same page, you can also configure the following return settings:
Define Return Window, i.e, set the time limit for a buyer to return a product.
Upload the products list for which you want to allow returns.
NOTE (FOR SHOPIFY CHANNEL ONLY): To unleash all the features like Auto Refund and Inventory Restock, grant all the required API permissions to Shiprocket App on the Shopify panel. Click Here to learn more.