Is purchasing an apartment with a down payment and the remainder of the price paid in installments with a known annual interest, despite the buyer's unwillingness due to the seller not accepting the full amount, considered explicit usury, and what is its ruling?

There is no harm in purchasing an apartment in installments directly from the seller at a higher price than its cash price due to the deferred payment, whether a portion of the price is paid or not. However, if the purchase is made through a bank or an institution that finances the purchase and defers the amount with an increase, then this increase is usurious and forbidden by scholarly consensus.