Hi there!
"this" is a javascript special keyword that can mean different things depending on the context. As so, it's best for you to take a look at visustella documentation to understand what context they are providing you on that formula.
Because the "this" keyword may not be referecing the actor, but something else.
If you are sure that "this" is referecing the actor, then you need to make sure that you created the custom parameter on the Plugin Parameter of my plugin and also added a value to it.
Remember:
- 0 = The first custom parameter
- 1 = the second custom parameter
and so on.