Is the borrower obligated to return the amount he took from the bank in the European country along with the accrued interest, or is it sufficient to return only the principal amount to the bank, or to pay it to an Islamic charitable organization?

The feature mentioned in the account, which is that the bank lends an amount and then reclaims it with an increase, is prohibited usury (riba). It is not permissible to take this money from the bank, nor is it valid to make it a substitute for another debt. Rather, the principal amount of the debt must be returned to the bank. As for the interest, it is not permissible to pay it. If it is impossible to return it, then it should be given as charity to the poor or donated to an Islamic charitable organization for the general benefit of Muslims.