If you still have an Openreach master socket in your house, plug the phone in there. Is there any tone, and are you able to make / receive calls that way?
Try phoning it from your mobile to check it responds.
To have VOIP you would need to have requested it specifically with your Full Fibre order. There's usually a £2 monthly charge to maintain a VOIP service through Talktalk now, before paying for any calls / boosts. It won't just work by plugging the phone into the back of the router, without previously setting it up during the ordering process, @Steve2477.
Gliwmaeden2, a fellow customer.
