If the "Sold Out" badge isn't displaying on your out-of-stock products in the featured collection or on specific products within the collection, it could be due to your inventory settings in Shopify.
STEP 1
Log in to your Shopify admin.
STEP 2
Go to Products and select the product that is missing the "Sold Out" badge.
STEP 3
Check the Inventory Settings:
Under the Inventory section, make sure that:
The Track quantity option is checked.
The Continue selling when out of stock option is unchecked.
Track quantity is not enabled, Shopify won’t be able to display the "Sold Out" tag because it won’t know when stock is depleted.
If Continue selling when out of stock is enabled, the product will still be available for purchase, preventing the "Sold Out" tag from appearing.