Register the standby server with:

    $ ltcluster -f /etc/ltcluster.conf standby register
    NOTICE: standby node "node2" (ID: 2) successfully registered

Check the node is registered by executing ltcluster cluster show on the standby:

      $ ltcluster -f /etc/ltcluster.conf cluster show

     ID | Name  | Role    | Status    | Upstream | Location | Priority | Timeline | Connection string
    ----+-------+---------+-----------+----------+----------+----------+----------+--------------------------------------
     1  | node1 | primary | * running |          | default  | 100      | 1        | host=node1 dbname=ltcluster user=ltcluster
     2  | node2 | standby |   running | node1    | default  | 100      | 1        | host=node2 dbname=ltcluster user=ltcluster

Both nodes are now registered with ltcluster and the records have been copied to the standby server.