Restore all databases via Terminal fails with "<NOROUTINE>"

Hello,

I have set up a Docker image with IrisHealth Community Edition and created a backup of all databases with the Management Portal. Obviously, the restore requires a different way, i.e. a terminal or session needs to be started to use a "Do ^DBREST".

Due to the manual first a session (which is probably same as iristerm terminal) needs to be started:

docker exec -it iris iris session iris

If I enter "DO ^DBREST", I get the answer:

<NOROUTINE> *DBREST.

I assume that when I start the session that way I get logged in as "USER", at least the prompt "USER>" indicates this. All the examples are for "%SYS", which may be the reason. I tried to log in via argument "-U _SYSTEM", "-U %SYS", "-U SYSTEM", but all fail with a permission denied error message.

Can anybody please help?