I am checking with the developers, but I believe you actually have to run the ./omnicli.sh then within the running app the command you’d run would be copy <src> <dst>, this is how it works on windows at least.
Just got a response from the devs. You can run ./omnicli.sh interactively, but you’d need to use the client library calls, which would be copy.
If at all possible, can we please get the logs from your attempt at copies. Talking with the eng team, they think there maybe an issue here, but we need more info please.