how to automate to load Currency rate

We are looking to automate the process of loading currency exchange rates into our Oracle Fusion Cloud. We found that the FBDI template is available , However, we would like to explore a more automated or integrated approach.
We do not have OIC license and therefore cannot utilize the standard prebuilt OIC integrations or adapters.
Can you help with below questions:
Is there a delivered web service or REST/SOAP API provided by Oracle for currency rate loading that can be used outside of OIC, such as via custom integration built using external middleware, or custom scripts?
If yes, could you please provide the details of the service (endpoint, payload structure, authentication, etc.)?