LG ThinQ TV is probably the first TV to ever require a 4-year degree to be able to set it up. Joking aside try this;
1. Set Turn on via WiFi on your TV
- Settings ->All Settings -> General -> Devices -> External Devices -> TV on With Mobile
2. On LG ThinQ app run Set to use Smart Speaker (this one is easy to accidentally skip on initial TV setup because it looks as if they are going to sell you their smart speaker, which obviously I don't want)
- 3 lines on upper left corner -> Device Settings -> Select your device -> Set to use Smart Speaker
3. You can try linking ThinQ again in Google Home. There is also a link to Voice Assistant in ThinQ app.
- 3 lines on upper left corner -> gear icon on upper right corner -> Voice Assistant
NOTE: Only On/Off is available when successfully linked. Google Home doesn't display any fancy remote control app.