Yahoo Stock API is deprecated as you know. Your webstore can not auto update the currency rates now. Don't worry, this patch will solve all the problem, it fixes this functionality for your store. Now every day your currency rates will be updated automatically.
This extension allows you to update currency values on your site to today's ACTUAL value from Currency Converter API tool. The simplest currency conversion service for software development.
CurrencyConverterApi.com : http://currencyconverterapi.com/
Automatically update your currency exchange rates based on your stores default currency
A manual update button on the Settings -> Localisation -> Currencies
Currency rates will be updated automatically every day
No need for a CRON job
A log file is stored in the logs directory for your site
Note: Due to an upgrade of the API used, the service allows a maximum of 2 currencies for the free version. So in total you can have 3 coins configured in your store for free, otherwise the service will return an error (25-08-2020)
If you wish you can subscribe to a plan for this service at this link, we will be able to install it.