Firstly, you need Vases. Gather the Peony Seeds that they drop and merge them until you reach level 5 or above. Peony flowers of these levels will drop Water Leaves. Merge them until you reach the level 8. This way you will get a Ship in a bottle. When you tap on this Ship in a Bottle, a Sailing Ship will spawn. Keep merging Sailing ships and you will finally get the Cargo Ship!
From here the process is much the same, you have to tap on the Cargo Ship to get the Shipping Containers. And taking their drops to get the Scarab box. Just bear in mind that Scarab boxes must have the nearby spaces empty, or they won’t drop and the item will disappear, be careful! Now you can merge the Scarabs to get the final pieces of this Merge Chain.