Transfer files from Sharepoint into oracle hcm cloud what is the method?

Hello ,

We would like the best convenient method to transfer files between outside SharePoint (outside fusion cloud ) into fusion. 

The best, friendly way to transfer manually and automatically. 

I know there is an option using HDL operated automatically or RestAPI. 

Is it a must to use the UCM as a middleware? 

And if so what will be the most friendly useful way for the users. ?

Thanks a lot,

Revital.