One product, multiple pack variations, and barcodes

Hello to all,

I have a product (single EAN) but I want to list multiple pack variations of it. Do I need additional barcodes for different pack levels, or is there another way to list multiple pack (of same item) without additional barcodes?

Such as same EAN same product but single pack, 3 pack and 5 pack variations. I am aware that I need to pack multiple packs together and label them with FNSKU, but getting barcodes from producer for multiple packs could be difficult.

Thanks in advance to all.