The conversion of 75 US dollars to Nigerian naira depends on the current exchange rate. Exchange rates are constantly fluctuating, so it's important to check with a reliable financial source or a currency exchange service for the most accurate rate.

Typically, to find out the exact amount in naira, one would multiply the amount in US dollars (75) by the current exchange rate. For example, if the exchange rate is 1 US dollar = 410 Nigerian naira, then 75 US dollars would be 75 * 410 = 30750 Nigerian naira.

However, as mentioned earlier, the rate can change daily. Banks, online currency platforms, and financial news websites are good places to monitor the latest exchange rates to determine precisely how much 75 US dollars in the form of an Amazon gift card would be worth in Nigerian naira at any given time.