Can any one advise me on what wire to interupt with a magnetic lanyard on a tw200, I'm assuming it's one going to the starter/kill switch on the bars. Bike is a 2021/22. Thanks

On trials bikes they usually go between the coil and earth, because the TW has a battery you probably do indeed want to use the engine kill switch from the handlebar controls instead ... for that you probably want to look up a wiring diagram (or use a multimeter) and then splice the lanyard wires between the relevant wires near where the switch cluster plugs into the wiring harness, usually in the back of the headlight