Couchbase Mobile and REST

I am experimenting with Couchbase Mobile, and I would like to understand more about how to use the HTTP and REST API. What I gather from the documentation is that there is a REST API available, but I’m not clear on where those request should be sent.

The APIs for iOS, Android, and .NET appear to create the mobile Couchbase database. I have a Couchbase Server installed, along with the Sync Gateway. Is it possible to use HTTP requests to perform all of the same operations that one of the native APIs (.NET, Java) can do, specifically replication? According to the documentation, it is possible, but I don’t see how… or how it would know where the mobile database is to do the replication?

Any information to get me over this hump and pointed in the right direction would be incredibly helpful!