Proper term for amount + currency

"Amount" is the closest single word. "Amount in dollars" would be the easiest way to specify information you are requesting. "Amount and currency" if you ware in an area using multiple currencies. An accountant might be able to give you a more technical term, but it would be accountancy jargon. Amount due, credit amount, debit amount, amount deposited, amount credited, amount withdrawn, or amount included. If you're writing instructions and want to specify that the person following the instructions needs to indicate the currency, you'll probably have to simply state that requirement.

Based on US centric thinking, inside the US, money is dollars, dollars is money. For US citizens outside the country, we would always tack on the currency. 100 dollars, or 100 Euro. There is a segment of Americans who do not understand geography, and that other countries exist, and that they use different currencies, might not realize that other countries have currencies named dollars, and that USD means US Dollars. So for U.S. citizens, be specific and clear.

Bottom line, if this is written for US residents, and they need to specify the currency, you need to explicitly require them to "List the amount and currency."