Do the differences resulting from currency conversion (whether an increase or a decrease) in sales made in Iraqi Dinars obligate the accounts manager to bear the decrease or own the increase?

It is not permissible to take the surplus, as it belongs to the company, unless there was a deficit taken from you unjustly and you found no means to recover it except from this surplus. This is known as the issue of al-Zafar (taking what is due to you by force). It is not permissible to sell goods on credit in dinars with the condition of repayment in another currency. However, it is permissible to take its value in another currency at the time of repayment without a prior condition.