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: