Create Demand Gen Video Ad

Creates an ad inside a Demand Gen ad group — a VIDEO ad (give youtube_video) or an IMAGE multi-asset ad (give image asset ids instead). This is the last step that makes a Demand Gen campaign able to serve, and the only way to run a click-oriented YouTube campaign now that Google moved Video Action campaigns into Demand Gen.

VIDEO ad: youtube_video accepts a bare video id, a watch URL, a youtu.be link or a /shorts/ link; the matching video asset in the account is reused if it already exists and created once if it does not. Headline <=40 chars, long_headline <=90, description <=90, up to 5 each. call_to_action is optional (LEARN_MORE, SIGN_UP, GET_QUOTE, CONTACT_US, SUBSCRIBE, DOWNLOAD, BOOK_NOW, SHOP_NOW, BUY_NOW, DONATE_NOW, ORDER_NOW, APPLY_NOW).

IMAGE ad (DEMAND_GEN_MULTI_ASSET_AD): leave youtube_video empty and give marketing_image_asset_ids (landscape 1.91:1, min 600x314) and/or square_image_asset_ids (1:1, min 300x300) — at least one of the two — plus optional portrait_image_asset_ids (4:5, min 480x600); 20 images at most in total. Ids come from list_assets or upload_image_asset (use aspect '1.91:1' / '1:1' / '4:5'). Up to 5 headlines <=30 chars and up to 5 descriptions <=90 chars; there is no long headline. call_to_action_text is the optional button text. headlines and descriptions take a list, or a string with one item per line (comma-separated also works when no item contains a comma). Google REQUIRES business_name (<=25) and a square logo for both types: logo_asset_id from an existing image asset, or empty to use the account's largest square image asset; if none exists, upload_image_asset uploads one. The ad is created PAUSED, so nothing spends until it is enabled. To edit the copy of an existing image ad later use update_rsa with its ad id. confirm=false -> preview.