Approval for Change Request/Ticket

[jacinth]

I would need the following for a Change ticket but I cannot find it in OTRS.
Agent will add an approver for a Change ticket. The approver will log in and approve or reject on this ticket (something like the decision page in normal ticket).

Is it possible for us to add approver in OTRS? Where should I add in?
Where will the approver approve/reject the ticket?

Thank you.