Please make sure to copy the value into the field Alternate Order ID of the media campaign. This will make sure that your offer number gets copied/transferred by the ADvendio Interface into the Google Ad Manager standard field PO Number.
To map other custom fields, please refer to the instructions here: 22.214.171.124 Map and transfer data into Google Ad Manager custom fields
Map the Campaign Items Alternate ID
By selecting a value for the Campaign Item field Alternate ID this value will be transferred to the field External ID in the Google Ad Manager Line Item.
If no value is set, the Salesforce record ID of your Campaign Item will be transferred into the field (Only available in versions lower than 2.111)
Change in Alternate ID Mapping
With ADvendio Spring 2019 (2.111) we will have a change in the Alternate ID Mapping for both Media Campaign and Campaign item for Google Ad Manager.
Before 2.111: ADvendio automatically pushed the Record ID from Salesforce into the External ID field in GAM, if no other value was set.
With 2.111: We removed this functionality. Now the External ID will only be set, if the field Alternate ID in ADvendio is filled. If you were using the Record ID in GAM (e.g. for reporting purposes) please create a workflow or similar to automatically copy the Record ID into the field Alternate ID.
Map the Account's External ID
To map the advertiser ID choose which field you like to transfer in the Google Ad Manager Adserver login:
This will lead to filling out the following field in Google Ad Manager