Galera cluster docker doesn't find the master machine

HI, I have a problem when implementing with Dockers a Galera Cluster, I have a virtual machine in which I have a docker galera master, and another virtual machine where I have another docker galera that depends on the aforementioned master.

The problem I have is that when I try to start the “slave” docker it dies because it does not find the master, any idea how I could do so that the “slave” could see the master.

Sample of the docker-compose document of both master and slave