Upgrading Codecs to 1.20.6

[CrypticVerse]

Description

I'm currently developing a mod that uses a custom Codec to serialize and de-serialize recipes.

        public static final Codec<MapleSyrupRecipe> CODEC = RecordCodecBuilder.create(in -> in.group(
                validateAmount(Ingredient.CODEC_NONEMPTY, 9).fieldOf("ingredients").forGetter(MapleSyrupRecipe::getIngredients),
                ItemStack.ITEM_WITH_COUNT_CODEC.fieldOf("output").forGetter(r -> r.output)
        ).apply(in, MapleSyrupRecipe::new));

        private static Codec<List<Ingredient>> validateAmount(Codec<Ingredient> codec, int max) {
            return ExtraCodecs.validate(ExtraCodecs.validate(
                    codec.listOf(), list -> list.size() > max ? DataResult.error(() -> "Recipe has too many ingredients!") : DataResult.success(list)
            ), list -> list.isEmpty() ? DataResult.error(() -> "Recipe has no ingredients!") : DataResult.success(list));
        }

I also know that there is a new MapCodec method in RecipeSerializer and packet codec method, and I don't know how to use these since the original method is Codec, not MapCodec.

How would I use and upgrade these from 1.20.4 -> 1.20.6?
Thanks!