Does the loss fall only on the borrower if he takes a loan from an Islamic bank to buy an apartment or a car and no longer has money to repay the loan?

The debtor is obligated to repay the debt, even if he goes bankrupt, and the debt remains his responsibility. The bank has no relation to the debtor's loss, but it is not permissible for the bank to increase the amount of the debt in exchange for late payment, for Allah Almighty says: "And if there is any debtor in difficulty, then grant him time till it is easy for him to repay; and if you remit it by way of charity, that will be better for you if you did but know."