Only available in Google Ad Manager 360
Audience Solutions is a Google Ad Manager 360 feature which might not be turned on for your network.
To target line items to audience segments:
- In the line item's settings, go to the "Add targeting" area and click Custom targeting.
- In the "-- select key --" drop-down list, select Audience segment.
- Select any other targeting criteria you want to apply to the line item.
- Click Save.