I want play embedded YouTube video in iOS app using YTPlayerView provided at https://developers.google.com/youtube/v3/guides/ios_youtube_helper
When I tried to play
By setting the origin property in my playerVars I was able to play the embedded video.
let playerVars = [
                     "playsinline" : 1,
                     "showinfo" : 0,
                     "rel" : 0,
                     "modestbranding" : 1,
                     "controls" : 1,
                     "origin" : "https://www.example.com"
                 ]
Then call loadWithVideoId:: as you normally would.

Swift 5.0
@IBOutlet weak var videoPlayer: YTPlayerView!
 self.videoPlayer.load(withVideoId: "M7lc1UVf-VE", playerVars: ["origin": "http://www.youtube.com"])
NSDictionary *playerVars = @{
                             @"origin" : @"http://www.youtube.com",
                             };
[self.playerView loadWithVideoId:@"videoId" playerVars:playerVars];`
This Objective-C version works for me.
YTPlayerView inturn uses iframes to play youtube video. You cannot use iframe in playing copyrighted youtube videos you can use a uiwebView to play this as an alternative