You can find the 'Wishlist' section in the upper right corner of the ‘Wardrobe’ tab.
To add items:
Tap the ‘Add Items’ button at the bottom of the ‘Wishlist’ section if you haven't got any items yet, or the ‘Add New Item’ in the upper left corner.
Take a picture of the item, or choose from the Stylix Library (add by pasting a product URL is coming soon), then tap ‘Add to Wishlist.’
You can also add items from any outfit recommendation in the app to your Wishlist. Tap on the outfit and tap on the heart icon in the upper right corner of your favorite item.