A price list item has a single EAN field. If you need to record multiple barcodes for one item, you have two options.

Each price list item can have up to five packagings configured, and each of them can have its own EAN code. You'll find packagings in the price list item detail, on the Additional specifications tab.

Use this method when it's still the same item, just in a different quantity or packaging (piece, box, pallet). The price is calculated by multiplying the sales price, and the barcode scanner will handle the packaging's EAN code correctly.

If it's actually a different item (a different variant, a different supplier), create a separate price list item for each code. In practice, this means physically relabeling the goods with the correct codes.