Is it obligatory to add what caused the inflation when paying off an old debt with paper currency to ensure fairness?

Paper currencies have value similar to gold and silver, and their rulings regarding exchange, zakat, and debts apply to them. The principle is that a debt is repaid with its equivalent, and it is not permissible to link it to inflation. However, if the currency's value decreases significantly and harmfully, its original value should be considered when repaying the debt to avoid harm to the right-holder.