We need to calculate the selling prices according to the secondary currency

Let me explain the problem a little bit. Our online store works with base currency in Chilean pesos because our payment method “WebPay Transabank” only works with base currency Chilean pesos. However our customers care much more about knowing the price in US dollars (which works with the plugin multi currency) but the problem is because the page automatically updates the prices with respect to the Chilean peso (which does not suit us for reasons of devaluation of Chilean currency) so we need the store to calculate the selling prices of products and automatically update according to the secondary currency USD. If you are so kind to help us to change the configuration so that our store calculates the prices taking as a reference the secondary currency American Dollars (USD).

Our store is https://cheveremercado.com/Ub1/t1/

Thank you in advance