On which machine we should install WAL-G?

We are using PostgreSQL version 12.1. Currently we have high availability and automatic failover using Patroni and it's working fine. Now we are planning for disaster recovery and we are planning to use WAL-G for this. We read some article to know that on which machine we should install WAL-G master, slave or both? But couldn't get a clear idea. Can you please help us to know on which machine should we set up WAL-G?