What is the ruling on using credit cards to purchase goods in installments online without interest on the installments, but with interest if payment is delayed, knowing that the cards are linked to the salary and do not allow for delay?

It is impermissible to use the aforementioned credit card because it includes a condition that obliges the payment of interest upon delayed installment payments, and this is considered usury (riba). The fact that the card is linked to the salary does not make its use permissible, due to the impermissibility of entering into a forbidden contract and accepting a usurious condition. It was stated in a resolution by the Fiqh Academy that it is impermissible to issue an uncovered card if it contains conditions for usurious increases. Even if no delay occurs, merely assenting to the usurious condition and signing it is forbidden, let alone the possibility that the salary might not be deposited for some reason, leading to a delay, and thus one becomes an agent for usury. The Messenger of Allah, may Allah's prayers and peace be upon him, cursed the one who consumes usury and its agent.