Yes dlt, Nicargua has it's own currency and it is Cordoba. Actually 1 US$ is equal to 19.18 cordobas.
US$ is accepted in some of the
Nicaragua hotels and restaurants. but your friend can get the local currency from the ATM's of
Leon. but when you do
shopping in Nicargua and if you are paying by US dollars make sure that you'll receive the balance in local currency. Even this too applicable during
dining in restaurants. hope this helps! best of luck!