Modern Vespa

I have an 18 plate GTS sie gorno that will not start. Fine day before. In morn turned over but wouldnt start. So first of all red light flashed 3 times which poss meant it didnt recognise the key. So i tried another key and it was ok. Just one red flash but still no start.
It turns over. Ive checked kill switch both levers. Side stand. Brake light comes on. Checked all fuses. Plug cap and plug. Petrol..
Smells like its flooded.
Any ideas please?

Check red kill switch.

Can't be that as the starter is working ("it turns over").

There seems to be fuel, which leaves faulty spark or timing. Timing going out so badly it won't start is very rare, but it's possible inlet valves are stuck.

So check the spark. If a good strong spark then it's valve cover off time. If no spark then chase that down - usually just a duff plug or bad connection in the cap, to either plug or wire.