Question on continuous replication between two local databases

[Alexander Harm]

Hi all,

I seem to be unable to figure out how to replicate between two local databases. 
I create the _replicator document as database admin and believe to have 
specified the roles correctly in the userCtx. However, I continue to receive 
error messages:
"unauthorized to access or create database mylocaltarget”

My initial _replicator doc looks like this:
{
    "_id": "myid", 
    "continuous": true, 
    "create_target": true, 
    "source": "mylocalsource", 
    "target": "mylocaltarget", 
    "userCtx": {
        "roles": [
            "_admin"
        ]
    }
}

Where do I go wrong?

Greetings,

Alexander