Finite State Machine

Hi! I am still fairly new to programming in unity and I have now come upon something that is a little perplexing to me. I have a finite state machine with 4 scripts: a state machine manager deriving from monobehaviour, an abstract class and 2 state scripts deriving from the abstract class. Now my question is: In which class I should read the input ? (I'm using the new input system and I have another script where I handle the call back context and the performed actions).