If your TV doesn't have the Play Store, you can manually install the app using an APK file—a process known as "sideloading". How To Download YouTube On Smart TV
: Use the search icon (magnifying glass) at the top and type "YouTube".
: Select the YouTube for Android TV app from the results and click Install or Download .
For most users, the standard YouTube app is readily available in the official store.
2. Sideloading (For Advanced Users or Non-Play Store Devices)