Please help if there is any guidance for the “core workflow” feature to create an approval feature that can only be seen by agents and customers can only choose which agent to request approval from.
Please have a look into the documentation which even has a basic example for exactly that.
https://admin-docs.zammad.org/en/latest/system/core-workflows.html
At least aprt from
as this is against Zammads Philosophy (aka a customer shouldn’t decide who works on their ticket)