As @Its_all_Nuts_again says, you need to study Seller U and Amazon policies about ASINs and "bundling."

They require UPC Codes that are different from single packs AND generally must be from the manufacturer. A (fairly) simple search for "bundling" would have found this:

"Product Bundling Policy

Sellers can create bundles composed of different products to create a new bundled product. Well-designed product bundles provide convenience and value to buyers. Adhering to the policies on this page will help Amazon customers locate product bundles more easily and prevent duplicate or near-duplicate listings.

General bundle policy

You may not list bundled products where the primary product in the bundle is from the Video Games category or is a Books, Music, Video, or DVD (BMVD) product.

You may include BMVD and Video Games items as secondary products in a bundle if they are related and complementary to the primary product in the bundle. For example, you can list a bundle composed of a yoga mat (the primary product), a yoga DVD, and a yoga book.

Bundle pricing must follow the Amazon marketplace fair pricing policy to ensure customer trust. For more information, go to Amazon Marketplace fair pricing policy.

The referral fee for the primary product's category (the same category used to list the product) applies to the entire bundle.

All products in bundles must comply with Amazon's Selling Policies and Seller Code of Conduct. More specifically, all products within bundles must adhere to the guidelines for each category.

Bundle images, features, and descriptions must also adhere to Amazon listing policies.

Failure to adhere to the Bundle Policy, including the following Detailed Bundle Guidelines, may result in the removal without notice of any bundled product listing, account suspension, or both. Amazon reserves the right to modify or revoke this policy at any time.

Detailed bundle guidelines

Bundle listing and categorization:

Bundles must consist of items that are complementary (this means items in the bundle enable or enhance the use of other items in the bundle or provide convenience to the buyer by purchasing them together) .

Bundles consist of multiple single items that can each be identified by a unique ASIN/UPC and are sold together as a single offering. A pre-packaged kit or pack with multiple items that is identified by a single ASIN/UPC is not considered a bundle.

A bundle may be listed in a single category only, even if the products comprising the bundle are from multiple categories. If a bundle includes products from multiple categories, it may be listed only in the category of the highest priced item in the bundle. The only exception to this guideline is if the highest priced item is BMVD or Video Games (because bundles may not be listed in these categories). In these cases, the bundle should be listed in the category with the second highest prices item that is not BMVD or Video Games.

The bundle must have its own standard product identifier or manufacturer part number. The identifier of any individual product in the bundle may not serve as the identifier for the bundle. Using a UPC from any single product in the bundle to identify the entire bundle may lead to immediate removal of the listing. You are responsible for obtaining a UPC for each bundle you create.

Do not include generic products in a bundle, as it may mislead customers into thinking the generic product belongs to the same brand as one of the branded products in the bundle. Generic products are identified as items with no brand on the product or packaging (not just widely unrecognized brands).

A bundle can be composed of different branded items, however the bundle itself should be branded according to the highest priced item in the bundle.

If an item is a multi-pack, such as six pairs of socks, list it as a single product and not as a bundle. See UPCs and Item Package Quantity for Multi-Packs.

If an item is a variation of a parent product, list it as a variation within the parent product’s family and not as a bundle. See About parent-child relationships.

If you match your bundle to an existing bundle listing, the products in your bundle must be exactly the same as the products in the existing bundle. If your bundle is different in any way, you must create a new bundle listing. You may not change the existing listing to align to the specifications of your new bundle.

Once you create a bundle, you may not modify the components of that bundle. If you want to add or remove products from the bundle, you must create a new bundle listing with a unique UPC or match to an existing bundle listing that is identical to your revised bundle.

Bundle warranties and returns:

If you list a product bundle, you must accept the entire bundle as a return and refund it as a single unit.

A bundle cannot contain any separate warranty products or extended service plans.

Bundle titles:

Bundle title length should align to title length rules in Amazon’s listing policy. This policy allows listings with a title length of maximum 200 characters (including spaces) in all U.S. categories.

Include the word "Bundle" and the number of items in the bundle in the product title. For example:

Bundle – 3 items: Tote Bag, Knit Scarf and Gloves - Blue

If the bundle includes only a few items, list them in the title. For example:

FORMAT

[Main Product title] + “Bundle with” + [Bundle Component Product title(s)]

EXAMPLES

"Kodak EasyShare C143 12MP Digital Camera Bundle with Rechargeable Batteries & Carrying Case – Blue"

If the bundle includes many items, list the primary and secondary items in the title, along with the total number of items in the bundle. In these cases, the entire bundle component information must be listed in the bullet points within the bundle details.

FORMAT

[Main Product title] + “Bundle with” + [Bundle Component Summary] + “(# Items)”

EXAMPLES

"Yamaha PAC112J Sunburst Guitar Bundle with Bag, Stand and Accessories (11 Items)"

Bundle product details and images:

Feature Bullet 1 in the detail page for your bundle must state that the product is a bundle of "X" number of items and must identify the products in the bundle.

The description in the detail page for your bundle must state that the product is a bundle and must also identify the products in the bundle (with appropriate designators, such as model number, color, and size).

The main image for the bundle must include the specific products in the bundle (and must not include any items that are excluded from the bundle). Images of representative or similar products are not permitted."