oAuth in AEM 6.5 Samples

Hi, we are running AEM 6.5. We have some application to application connectivity, whereby we have a on-premises Java applicaiton which is calling an API on a cloud hosted AEM 6.5 instance. We want to add in oAuth for the authentication piece, but can not find any sample in the Adobe documenation of how this can be done. We can see examples in  older versions of AEM 6.5 but the oAuth libraries in the examples seems to have been removed in the newer AEM versions.

Any assistance would be greatly appreciated!