Init struggle

[angel129116]

I'm running the Koel app in container manager on Synology NAS drive. All seems fine and has installed and I can get to the login page.
I'm struggling at the step of init for the first time

I can't seem to get the command docker exec --user www-data -it <container_name_for_koel> bash to run via container manager. I'm opening terminal and entering continer name but it just keeps erroring out with command ignored.

I know It's something I'm doing wrong but wondered if anyone could offer any advice. In containter manager I've got the Koel listed with project. Under I'm showing two options. One Says "koel-koel-1" and another says "koel-database-1"