IImpulseCommand.cs

public interface IImpulseCommand
{
    void Excute();
}

InputHandler.cs

public class InputHandler
{
    public IImpulseCommand ACommand;
    public IImpulseCommand BCommand;

    public void Update()
    {
        if(Input.GetButtonDown("A"))
            ACommand.Excute();

        if(Input.GetButtonDown("B"))
            BCommand.Excute();
    }
}

InteractCommand.cs

public class InteractCommand : IImpulseCommand
{
    private PlayerBehaviour _player;

    public InteractCommand(PlayerBehaviour player)
    {
        _player = player;
    }

    public void Excute()
    {
        _player.Interact();
    }
}

JumpCommand

public  class JumpCommand : IImpulseCommand
{
    private PlayerBehaviour _player;

    public JumpCommand(PlayerBehaviour player)
    {
        _player = player;
    }

    public void Excute()
    {
        _player.Jump();
    }
}

Startup,cs

using UnityEngine;

public class Startup : MonoBehaviour
{
    [SerializeField]
    private PlayerBehaviour _player;

    [SerializeField]
    private InputHandler _inputHandler;

    private void start()
    {
        _inputHandler = new InputHandler();
        _inputHandler.ACommand = new JumpCommand(_player);
        _inputHandler.BCommand = new InteractCommand(_player);
    }

    private void Update()
    {
        _inputHandler.Update();
    }
}