I was able using a different account which is a Google suite user to create an api key and define an internal application where no verification takes place
I can make a search, click on the arrow icon to listen to a youtube track but still no luck to hear something
Nov 07 20:48:35 volumio volumio[1188]: info: CorePlayQueue::saveQueue
Nov 07 20:48:35 volumio volumio[1188]: info: CoreCommandRouter::volumioPushQueue
Nov 07 20:48:35 volumio volumio[1188]: info: CoreStateMachine::updateTrackBlock
Nov 07 20:48:35 volumio volumio[1188]: info: CorePlayQueue::getTrackBlock
Nov 07 20:48:35 volumio volumio[1188]: info: Added undefined
Nov 07 20:48:35 volumio volumio[1188]: info: Youtube::addVideo
Nov 07 20:48:35 volumio volumio[1188]: info: CoreCommandRouter::volumioAddQueueItems
Nov 07 20:48:35 volumio volumio[1188]: info: CoreStateMachine::addQueueItems
Nov 07 20:48:35 volumio volumio[1188]: info: CorePlayQueue::addQueueItems
Nov 07 20:48:35 volumio volumio[1188]: info: Adding Item to queue: 1VaEdKwXJhM
Nov 07 20:48:35 volumio volumio[1188]: info: Exploding uri 1VaEdKwXJhM in service youtube
Nov 07 20:48:35 volumio volumio[1188]: info: Youtube::explodeUri https://youtube.com/oembed?format=json&url=1VaEdKwXJhM
Nov 07 20:48:35 volumio volumio[1188]: info: Youtube -> {"kind":"youtube#video","etag":"LrI1trJoiI0PapV5_9sYurvYrhk","id":"YtXq-v9XoMc","snippet":{"publishedAt":"2010-08-16T22:30:23Z","channelId":"UCy8_9W_De8bb-QeBxAAe00w","title":"Van Halen - Top Of The World","description":"Song - Top Of The World\nAlbum - For Unlawful Carnal Knowledge \nYear - 1991\nArtist - Van Halen\nGuitar - Eddie Van Halen\nKeyboards - Eddie Van Halen \nDrums - Alex Van Halen\nBass - Michael Anthony\nVocals - Sammy Hagar","thumbnails":{"default":{"url":"https://i.ytimg.com/vi/YtXq-v9XoMc/default.jpg","width":120,"height":90},"medium":{"url":"https://i.ytimg.com/vi/YtXq-v9XoMc/mqdefault.jpg","width":320,"height":180},"high":{"url":"https://i.ytimg.com/vi/YtXq-v9XoMc/hqdefault.jpg","width":480,"height":360}},"channelTitle":"andrewragford89","tags":["van","halen","top","of","the","world","for","unlawful","carnal","knowledge"],"categoryId":"10","liveBroadcastContent":"none","localized":{"title":"Van Halen - Top Of The World","description":"Song - Top Of The World\nAlbum - For Unlawful Carnal Knowledge \nYear - 1991\nArtist - Van Halen\nGuitar - Eddie Van Halen\nKeyboards - Eddie Van Halen \nDrums - Alex Van Halen\nBass - Michael Anthony\nVocals - Sammy Hagar"}},"contentDetails":{"duration":"PT3M54S","dimension":"2d","definition":"sd","caption":"false","licensedContent":false,"contentRating":{},"projection":"rectangular"}}