The bar in the back of the ignition switch isn't engaging the slot in the frame to create the steering lock. Either the bars are not going far enough to the left to allow it or the ignition block is faulty or the frame has been messed with. You could try this: Turn the bars fully to the left so you hear it bounce off the stop and hold it there. Insert the key and turn it to the locked position and then slowly move the bars back towards the right and see if it engages. If not, then start taking the front off to investigate
If you can hold a screwdriver and have half a brain you could solve this yourself quite easily. Just because it's something you've not done before, doesn't mean you can't do it. I have the scooters workshop PDF which I can send via email, easy to follow, if you decide to have a try. Where in the world are you based?