You can find Klarna as a payment option at checkout, and it is only available for one-time orders. Paying with Klarna gives you the ability to choose from one of the options: pay in 3 terms and pay in 30 days (pay later).
To clarify, Klarna is available for orders placed in the UK, US, Sweeden, and Germany. If you’re unable to find this option at checkout, could you please take a screenshot and send it over to us at team@huel.com?
Regarding your open pouch, the shelf life of Huel Powders is three months, and Hot & Savour is one month after opening. Having said that, if your pouch has been opened for longer than this and kept in dry, cool conditions, your Huel should be safe to eat but there are no guarantees and the nutrition will not be optimum.