In Diablo 2 Resurrected, to use the Horadric Cube to add sockets to your weapons, armor, shields or helmets, you need to complete the Act 5 quest, Siege On Harrogath. When you add sockets to items, you can put gems and runes in them to make them more powerful. If you put Buy Diablo 2 Resurrected Runes the combination of runes into the sockets in the correct order, it can result in very powerful rune items, which is the main reason why many players want to add sockets to their items.

When using Horadric Cube to add sockets to an item, one of the important factors is the level of the item, however the cube does not necessarily add the item to the maximum socket number, but rather a random amount between 1 and the maximum number of the item . That is, if your maximum number of sockets is 3, the cube will randomly add one to your Diablo 2 Resurrected Items for Sale item between one, two or three sockets. It's all up to your luck, you have no control over the process. So, when using the Horadric Cube, you will often end up with an item with the wrong number of sockets, however, unlike Larzuk, you can use it multiple times for your purpose.

And here is the recipe for adding sockets using the Horadric Cube:

Adding sockets to weapons requires the use of Ral runes, Amn runes, and the perfect Amethyst to transform normal weapons.
Adding sockets to the armor requires the use of Tal Runes, Thul Runes, and the perfect Topaz to transform normal armor.
Adding sockets to shields requires the use of Tal runes, Amn runes, and the perfect Ruby to transform normal shields.
Adding sockets to helmets requires the use of Ral Runes, Thul Runes, and the perfect Sapphire to transform normal helmets.

In general, adding sockets to your items using Horadric Cube is a long process because the number of sockets converted is random. If you don't want to go through the experience process, you want to get the items you need faster. You can check out MMOWTS, they sell Diablo 2 Resurrected Items with various socket counts, everything you need is available there, go try it!