How to configure automatic currency exchange rate update
First, you need to install Solidres Currency plugin (available for all subscribers) via Joomla Extension Installer, then enable it in Joomla plugin manager. Note that this plugin requires Solidres v0.9.3+ and your PHP configuration must support CURL or allow_url_fopen. If not, you will receive a warning message.
Now in the backend, you will be able to use the button "Update exchange rates" in List Currencies menu of Solidres.
There are two ways to update: manual and automatic
To update, you can check all the available currencies or just check the currency that you want to update the list then click "Update exchange rate" button. Solidres will automatically download the latest currency exchange rate from European Central Bank and update your selected currencies.
If you prefer Solidres to automatically update your currency exchange rates in a fixed time interval, you can use the command line version of Solidres Currency plugin which is stored in your Joomla_ Site_Root/cli/cronCurrency.php (copied from /plugins/solidres/currency/cli/cronCurrency.php) and configure to execute it via cron job/scheduled task. For more information how to setup cron job/scheduled task, please check the following resources or contact your hosting providers.