First you'll need this structure:

Apex Crafting requires "Bases" and "Catalysts".
The chest on the very top contains the item you want to enchant and all "Bases", with the item to enchant always being in the first slot.
The chests on the side are all individually filled with "Catalysts", EACH chest needs the mentioned "Catalysts".

Once you're sure your "Bases" and "Catalysts" are correct, use an "End Crystal" on the Chest at the very top(if something is incorrect, check your logs).
An Animation start playing (be aware, hitting any of the crystal can still cause explosions).
After thus Animation, the Chest at the very top will now have your item you wanted to enchant, with said Enchantment.

Be warned, some Enchantments will prevent you from getting any other new Enchantments on said Item.
And some can prevent you from giving an item yet another Apex Crafting. (Can be removed by combining said item with Rabbit Foots in an Anvil)

Creating an Apex Crafting Recipe

Datapack Path: data/uniqueapex/recipes/name.json

{
    "type": "uniqueapex:fusion",
    "ingredients": [
        {
            "input": { "item": "minecraft:heart_of_the_sea" },
            "amount": 1
        },
        {
            "input": { "item": "minecraft:obsidian" },
            "amount": 128
        },
        {
            "input": { "item": "minecraft:sponge" },
            "amount": 6
        },
        {
            "input":{
                "type": "forge:nbt",
                "item": "minecraft:potion",
                "nbt": { "Potion": "minecraft:strong_swiftness"}
            },
            "amount": 4
        },
        {
            "input":{"item":"minecraft:netherite_block"},
            "amount": 4
        },
        {
            "input": { "item": "minecraft:enchanted_golden_apple" },
            "amount": 2
        }
    ],
    "enchantments": [
        { "type": "minecraft:soul_speed", "level": 3 },
        { "type": "minecraft:efficiency", "level": 5 },
        { "type": "minecraft:channeling", "level": 1 },
        {"type":"minecraft:mending","level":1}
    ],
    "lock": true,
    "max": 5
    "output": "uniqueapex:aeons_fragment",
    "output_mode":"average"
}

"enchantments" are the Enchantments to consume(also known as "Bases"), the level indicates the minimum level the enchantment has to be
Lock will prevent the item from being used in yet another Apex Crafting Process as Receiver. (Lock can be removed with Rabbit Foots in the Anvil)
Max allows to limit the maximum amount of Enchantments that can be active at once for an item that received said Enchantment by this craft.
OutputMode defines how the output enchantment level should be calculated. Multiple options:
Add results the sum of levels used by "Bases".
Average results the average level rounded down used by "Bases".
Min results the lowest level used by "Bases".
Mul results in Enchantment levels of all "Bases" being multiplied with each other.
Max results in the highest level used by "Bases".