Is it permissible to convert the mentioned debt amount to its equivalent in gold, and if not, should the debt be repaid in gold or money?

The loan must be repaid in the same currency in which it was given (Syrian Lira). It is not permissible to agree beforehand to repay it in another currency or in gold, for fear of falling into usury (riba). However, at the time of repayment, it is permissible to agree by mutual consent to repay in another currency or in gold at the market price of the day of repayment, provided that the exchange takes place in the same session of the agreement, based on the hadith of Ibn Umar (may Allah be pleased with both of them): "There is no harm in taking it at the price of its day as long as you do not part and there is something between you." As for the excess amount you paid, it is a debt that must be recovered as money.