The thing holding the bowl on is the solenoid and should have a wire fitted to it.
The wire should show battery voltage when ever the key is turned on
If the plug has 2 wires then the other should be ground all the time.
The pin in the solenoid should retract when energised .
Because it is at the very bottom, the hole the pin runs in gets full of crud & gum so prevents the pin from moving .
So get some carb cleaner and clean the pin.
Push & pull it spray some more goo on it , push & pull some more.
Continue till the pit "pop" up when let go.
Or you can replace it, but they are frightfully expensive and I have never found one that would not clean up, eventually .
Conversely you can replace it with a bowl bolt.
This is ILLEGAL because you have tampered with & removed and anti pollution device but at least your grass will no longer be tall enough to provide habitat for lions & tigers.