How do i create a "Buy 2 for £X" voucher?

Is it possible to set up a voucher where if a customer buys 2 x a product they get X amount off?

Example - https://www.amazon.co.uk/dp/B0DTV4SSGP

I want to set up a voucher where by if a customer:

- Orders 2 of our single packs, they get it for £10, instead of £11.

- Orders 3 of our single packs, they get it for £14 instead of £16.50

TIA