Hello, i have a train ticket, stansted to liverpool street( great anglia) , liverpool street to paddington ( elizabeth line) and paddington to bristol. I dont need anymore to go stansted airport and not possible to change my train ticket. Can i start my journey at liverpool street at elizabeth line? if i do not use it stansted airport for the first train, can i use it the other connected trains? Any activation needed? If needed i will buy another ticket.