Hi Petra,
To explain further, you would need to first determine the campaign type and use the appropriate Audience builder for the campaign. You can only use the
targeting().newUserListBuilder for Search Campaigns. Use the
display().newAudienceBuilder() for Display Campaigns. For Shopping Campaigns, use
targeting().newUserListBuilder() method instead. Please see code below for your reference:
var displayCampaign = AdsApp.campaigns().get().next(); // filter display campaigns
var displayAudienceBuilder = displayCampaign.display().newAudienceBuilder();
var searchCampaign = AdsApp.campaigns().get().next(); // filter search campaigns
var searchAudienceBuilder = searchCampaign.targeting().newUserListBuilder();
var shoppingCampaign = AdsApp.shoppingCampaigns().get().next();
var shoppingAudienceBuilder = shoppingCampaign.targeting().newUserListBuilder();
Furthermore, Affinity and Interest Audiences can only be applied to Display Campaigns.
Hope this helps. Let me know your thoughts.