The value of a $20 Amazon card in Nigerian Naira can vary depending on the current exchange rate. Exchange rates are constantly fluctuating due to various economic factors such as inflation, interest rates, and market demand.

To determine how much a $20 Amazon card is in Naira, one needs to check the prevailing exchange rate. This can be done through financial news platforms, online currency exchange services, or even at local banks. For example, if the exchange rate is 1 USD = 410 Naira, then a $20 Amazon card would be worth 20 * 410 = 8200 Naira.
It's important to note that when converting the value, any associated fees or charges should also be considered. Some currency exchange methods might have additional costs that could slightly affect the final amount in Naira received for the $20 Amazon card. Additionally, it's advisable to compare different exchange options to ensure getting the best possible rate for the conversion.