LG Web browser - LG Web OS binding - Youtube video

Dear community,

I successfully use OH3 + LG WebOS binding to control my LG TV.
Now I plan to use OH to send a Youtube video link to the LG Web Browser and to display the video in full screen mode right after the video has been loaded.
It basically functions with rule action “launchBrowser(YouTube
The video automatically launches, however, the video uses only entire browser area but not the full TV screen. When I use the TV remote control and click the full screen sign at the buttom left corner it switches to the full screen mode though.
Does anyone know what I need to do to display the video immediately in full screen mode?
Any comments, hints etc. are highly appreciated.

Thx, Rc