Activating ECMA-script 2021 for OH3 in docker

Running OH3.3-release in a docker on my Synology - and JSScripting is installed.
Still only get ECMA 5.1 or DSL to chose from as action in a rule.

How can I activate EMCA-Scripting 2021 for rules in there? Docs say, I’d have to use npm, but Docker doesn’t know that? thanks!

nevermind - restarting the container did solve it.