Zammad 6.0 is not current either, you really should also upgrade this to the current version.
That being said, we use Macros, Triggers and Schedules for these sort of things, even for one-off tasks, just because this works really well and depending on the situation, we can use various methods.
Thanks a lot for your reply, I think it can be handled by trigger. I’m also “interested” in the upgrades of Debian, Elastic Search and our Zammad version, but since it’s our production environment, I would like to seek your further advice if there is an instruction on how to do the upgrade? I’m not an expert with such experience so as detailed advice as possible:)
If it’s your production system and you have no way of testing the upgrade path, or if you’re not comfortable doing it by yourself, I would consider asking for expert guidance and contract Zammad’s Professional Services for paid support.