What i see in magento 2.2 and 2.3 is that Webservicex and Yahoo Finance Exchange are removed.
Why are they removed? What are the alternative to them? How can i add them back?
It seems Yahoo and webservicex has deprecated their Currency Converter Api Service. In Magento 2.2 you will find an service not found error. Try this module https://github.com/thanhdv2811/Magento-2-Currency-Convert