You can download any Karaoke apps from the Play Store on your Android TV. Few of the best ones are listed below:
- Starmaker
- Smule
- Karaoke Anywhere
- KaraFun (has remote control)
For the mic part, Android TVs support Bluetooth mic input. You can either use a Bluetooth-enabled remote with voice input support (Google Assistant) or a dedicated karaoke Bluetooth mic for the matter.
Since it is Android 11 you should be able to connect more than one multi-point Bluetooth device. I can see that your TV is pretty high-end and has Bluetooth 5.0 (specs) which indeed supports multipoint connections.*
Alternatively, you can buy a karaoke set that combines the two mic inputs before sending it to the TV, which makes things super smooth (recommended)
Video for reference
Few Bluetooth mics (Amazon,UK).. (shared links don't seem to work since I'm not from UK so I'm just adding the names)
- MAONO Bluetooth Karaoke Microphone, MKP100 (Recommended)
- ACESHOP Karaoke Wireless Microphone Portable Handheld
- EKLEVOR Wireless Microphone, Karaoke Bluetooth Microphone