RouterOS provides SSH client that supports SSHv2 logins to SSH servers reachable from the router.
For this command to be available router has to have system and security packages installed.
/system ssh [remote-ip]
In this case the username thats provided to the remote host is the one that is logged into the source router.
/system ssh 192.168.88.1 user=bob1
If an other value for username is required, then user= has to be used as above.