You can also try HOME > Help and Settings > Help > Set up Remote. Follow instructions there it should give you a series of codes to try. You can also put 0999 in place of the code and press channel up until the TV turns off, then press ok.
You can also download and use the TV Control app to a) control your TV and b) set up your remote Download link
The Service you do for others is the rent you pay for your room here on Earth - Muhammad Ali
Thanks for the feedback. Sorry, I should have mentioned that I've also tried the 0999 code and was typing the channel up arrow for about 5 mins before conceding that there was no code for my new TCL OLED TV. The Virgin Media tech support person also talked me through resetting my old V6 remote and trying to set up from scratch. They are sending an engineer tomorrow but can't say I'm feeling confident that person will be able to do anything different than I've already tried already.
Unfortunately, TCL Facebook was of no help. Part of me regrets buying the TV. I know you get what you pay. I was initially unsuccessful in being able to speak to anyone from the customer support and after someone from the FB messenger finally got someone (apparently only 1 person on their customer support) to speak to me, the response was that they highly recommend that I do not sync one control to use both TV and V6 box.
The Virgin Media engineer was also unable to sync the V6 remote so I have to use the TCL control for vol and on/off.