Is it permissible to purchase with a bank credit card in installments, whether with or without interest? And is it permissible to deal with a person who buys electronic devices and offers them in installments?

Purchasing appliances with a credit card is permissible if no usurious interest is incurred, whether for the buyer themselves or for selling at a profit. It is forbidden if usurious interest is incurred. It is not permissible to assist someone who intends to engage in a usurious transaction, such as encouraging them to purchase with a credit card that involves usurious interest, based on the Almighty's saying: "And cooperate in righteousness and piety, but do not cooperate in sin and aggression," and the Prophet's (peace be upon him) prohibition of usury and those who deal in it. However, if the purchase with the card does not involve usurious interest, then there is no objection to the transaction.