Multiple Node as Master Redis CRDB

I’ve issue with CRDB Redis Geo-Distributed when i joining a node to existing cluster (1 cluster have 2 node), but after joining the node, the 2nd node become a slave. Can i make the 2nd node as master, so i can have master-master? Or how can i configure it to create master-master node in 1 cluster?
In the end, i want to have 1 cluster with 2 nodes and the nodes status is master-master not master-slave.
Thank you in advanced.