Maybe there is already an answer to that question, but I didn't find it. If this is only a duplicate I would love to get the link to the original post

I'm currently trying to build a setup with that I can prevent Agents, to move Tickets to another Queue if the Ticket hasn't set a Customer.
My Idea was to set up ACL to get this idea working. But with the documentation I read, I'm not quite sure how to modify the ACL to my needs. (How can I check if Customer is none?)
If anyone has an Idea I would love to hear it

Thanks in advance!
Daniil