To traffic line items, Ad Manager automatically activates them once you've added a creative of each specified size. You can also activate them manually before you've added all the creatives.
However, if you want more precise control of when line items become active, you can require that all line items be activated manually. Even if a trafficker has added all of the required creatives, the line item doesn't change its status to active or begin running until the trafficker manually activates it from within the line item's settings.
- Sign in to Google Ad Manager.
- Click Admin Delivery Delivery settings.
- Deselect the Automatic line item activation checkbox.
- Click Save.
Currently active line items aren't affected, but all inactive line items will need to be manually activated before they can be delivered.