How do you use FHttpRetrySystem? There's literally zero documentation on how to use it

There’s literally zero documentation about how to use FHttpRetrySystem. Fortnite seems to use it but why is there not even one documentation on how to use it? How does one use it, for example, to retry Gateway Timeout?

I’ll just make my own retry system with configurable backoff policy, because looks like this FHttpRetrySystem only has constant interval anyway.