Klarna is a company that lets you buy things online, usually expensive items like clothing, maybe, or electronics, and you buy it on credit and then you pay it back in installments.
Banks also finance consumer purchases by paying for credit card purchases by people who later reimburse the credit card companies and the banks behind them, by paying monthly installments that include interest.
I don't think Jerry, well, we know he doesn't have the liquidity to even buy the club outright, because he had to borrow the money from Gordon Singer, from Elliot before, and he's paying it back in chunks.