Hi, if the fsm is on the chest you can use a 'System Event' transition.
Right click on a state, select 'add transition' or 'add global transition' and then 'system event'
There you will find 'Get Mouse Down'
after you placed this you can click on the object while playing and the Transition will be triggered.
There is also an action called 'Get Mouse Button Down' but this one will trigger on the whole screen, no matter where you click.
This one can be useful with a mouse pick event especially when you have lots of objects, because if you would have a lot of objects with the System Event it will get laggy.
here is a sample video :