Hi Prateek -- We don't currently support server-to-server calls to external services from endpoints. However, we're developing this feature right now. We're running a limited beta in the version 13.3 release (which will ship to customers starting next week) and expect for it to be available to everyone in the next few months.
If you (or other developers who see this thread) would like to participate in the beta, send me a PM and we can discuss the eligibility criteria. The beta will only support a limited set of use cases and we're keeping the number of participants small.
