Well this is not as easy as it appears. I asked both the check in agent and the FL agent at LAX to print me my e-ticket receipt showing my baggage allowance. Both could only print me an e-ticket on a BP which shows fare, taxes, routing etc.... but it does not show baggage allowance. The TA at LAX printed me the fare rules of baggage to UK

Next step is to call the EXP desk and ask them to send me something which does show it.