Can I use BRL for the US visa fee in Asuncion?

I am travelling to Asuncion, Paraguay as an American. Paraguay levies a reciprocity fee of $160, which must be paid in cash.

I can pay this upon arrival, and multiple sources mention USD, but it's not 100% certain.

I am currently in Brazil; a quick calculation says the fee is roughly R$ 500 at current exchange rates; will I be able to bring this amount to pay?

If not, might there be an ATM from which I could withdraw USD? I'd like to avoid paying the exchange bid-ask if possible.