What is the ruling of Islamic law regarding dealing with the change in the foreign currency exchange rate when paying the price of an apartment that was agreed to be purchased in installments with a foreign currency, and is it possible to reclaim the amount paid or negotiate a new price and payment date?

If you purchase an apartment with foreign currency, the price must be paid in that currency as per the contract. You are not entitled to annul the sale or deduct from the price due to an increase in its value unless the seller agrees. However, if you purchased with your local currency and the seller stipulated payment in a foreign currency, this condition is invalid, and you must pay in the agreed-upon local currency. If a dispute arises, the religious judiciary is the reference.