Happy to help! I would suggest making use of lambdas - https://docs.microsoft.com/en-us/dotnet/csharp/language-reference/operators/lamb...
So in your case, something like this...
It is not necessary to store the lambda in a local variable ("conLambda"), typically I would just pass it directly as the second parameter of AddFieldCallback, but I broke it out into its own line for clarity.
The basic way I think about lambdas is that they declare a function that operates on a given set of parameters.
(param0, param1, etc.) => [turns into] [action on parameters]
In this case, your function operates on no parameters, hence the empty parentheses at the start of the lambda declaration.
From the perspective of the InkObjects system, using an Action with no parameters makes the most sense for a FieldCallback, as the system does not have any data that it needs to pass along when it invokes the action (though I could imagine a very complete system might want to pass along the name and value of the field that is being updated, and maybe I will push an update later that has that functionality, but it wouldn't accomplish what you are trying to do).
Anyway, let me know if you have further questions or encounter any other issues!