3.1.5.2.1 Interstitials (Google Ad Manager)
If you want to use Interstitials you will have to create a matching Ad Type. To match the "creativeSizeType" Interstitial in Google Ad Manager do the following:
Pick the value "Out-of-page" for your slot size.
If the picklist value "Out-of-page" is not available in your Org, please request your administrator to create it and assign it to the ADMANAGER record type, making sure to follow the correct spelling:"Out-of-page".
Interstitial creatives are only supported for publisher-managed creatives. To set this up, navigate to the field “Creative Source” on the Campaign Item level, where you can pick from two values “Publisher” or “Advertiser”, pick “Publisher” as a value for this field.
, multiple selections available,