Create a new Ad or Pre-roll:

Pre-existing video content can be defined as an Ad and assigned to a main asset: see Assign an Ad or Pre-roll to an Asset.
To upload new content to the MediaStore as an Ad or Pre-roll, follow the steps below.

1. In the navigation sidebar, go to + Create New > Asset
2. Drag and drop or browse your files to upload your video ad or pre-roll
3. Select Ad in the Type field
4. In Main Asset, choose one or more parent video assets for the ad or pre-roll to screen with
5. Select an Access level
6. Complete the remaining metadata fields (see: Upload an Asset for details) 
7. Click Finish