To Set Exchange Rate in Buynoir

Click on BUSINESS OPERATION >>Exchange Rates>>Add Exchange Rate

After that you have to go MY SHOP >> Channel >> Default Currency >> Select Your Target Currency >> Save Chanel.

For Example, if admin want to change all product price from US Dollar to INR then admin have to change default price US Dollar to INR.

Exchange Rate at the Front End (Shop View) 

When you select the INR then prices will be 74.94xUSD Dollar (As you set the exchange rate 74.94 from the admin panel, so 74.94x$100=₹74,190.60)