Q Money answer
The core currency set is based on European Central Bank reference rates retrieved through Frankfurter. When the ECB does not publish a pair directly, the website can derive a cross-rate from the relevant euro reference rates.
Currencies outside the ECB reference set use a separate extended provider. Each rate surface identifies its source so that an extended figure is not presented as ECB data.
Reference figures shown on qmoney.app are indicative and are not executable transaction rates.