Hoe can I use OAuth and dedicated user in Service Connection in VBS to access Oracle Fusion Data

We are working on a Custom AppUI development in Oracle Fusion Application as extension using Visual Builder Studio. Where we need to access some oracle fusion data like Supplier and Purchase Order information and we want to use some named user in the Service Connection who has the respective role instead of using the Oracle Cloud Login, the current logged in user . How can I achieve that?

Any help on this will be highly appreciated.