How to forward a workflow without agent to the administrator?

Hi,

I have an invoice that was approved but after that it was not sent to the next approver.

Looking in the history of the invoice I saw that probabbly it was not sent to the next approver because it doesn't have an "Agent" assigned.

Not sure if that is the reason but anyway I would like to send this workflow back to the administrator. How can I do that?

Here is a screenshot of the invoice without an "actual Agent":

Thanks!
Carlos