Open Control Center, tap Screen Mirroring and choose the TV. Then turn it on its side.
The steps to show an iPhone's or an iPad's screen on a TV with AirPlay, under the heading AirPlay (not translated): Control Center and Screen Mirroring as Apple calls them in iOS in this language (use Apple's own words in the language). Then to turn the phone or iPad on its side, as the big screen is wide
Apri u Centru di cuntrollu, tocca Duplicazione di u screnu è sceglie a TV. Dopu, gira l'apparechju di fiancu.
