Signing into the YouTube app on the TV under your account on this service. In the settings menu, locate the "Bind device". TV will give the link to pair and a code. Will also be shown a QR code which you can use the smartphone's camera to convert into a link.
On your smartphone, laptop or computer go to YouTube app and select Settings — Connected TVs. Is there a button to Add a TV. Enter the code received from the TV. If you want to work with the service of videos through the browser, then click on the link of the TV. In the end it should be written pair. There will also need to enter the code.
Now any video link from social media or just search on the smartphone or laptop, you will be able to watch on the big screen. Also available to put video in the queue watching it on TV. Opens the total list of previously visited YouTube videos on smartphone and TV.