Documents in Print queue won#t be printed unless someone login

Hi, I have a Windows Server 2012 R2, in this Server I have some Services that every morning reads some text from a web Server and write These data into some text files and then send them to a Network connected Printer.

My problem is, the Printer will not print These until someone Login, the print Job will be listed in the Queue but it won't be printed unless someone logon on the Server.

I want to how can I Change this behavior?

Thanks