Accessing GraphDB with RDF4J with an specific user

Question

I'm using RDF4J to add RDF triples to a completely open (Security off) GraphDB instance. I use the RemoteRepositoryManager and it works fine:

RepositoryManager repositoryManager = new RemoteRepositoryManager(GraphDBInstanceURL);
Repository repository = repositoryManager.getRepository(graphDBrepoName);
RepositoryConnection repositoryConnection = repository.getConnection();

Now we need to add security to GraphDB, but it is not clear to me how to add the specific GraphDB user credentials in the above code. Any pointers are wellcome, thanks