TMP Input Field not accepting new input system

Hi there, i’m using TMP_InputField and it throws this error
You are trying to read Input using the UnityEngine.Input class, but you have switched active Input handling to Input System package in Player Settings.

this happens becuase in line 1674 of the Input field class there is a call for the old input system

bool shift = Input.GetKey(KeyCode.LeftShift) || Input.GetKey(KeyCode.RightShift);

when i’m trying to change the line to update to the new input system i’m adding a reference to the head of the class file

using UnityEngine.InputSystem;

and change the problematic line to

bool shift = Keyboard.current[Key.LeftShift].isPressed || Keyboard.current[Key.RightShift].isPressed;

but then I get this error from the input field class file
The type or namespace name 'InputSystem' does not exist in the namespace 'UnityEngine' (are you missing an assembly reference?)

does anyone knows what I should do in order to update and change the input field class so it can exapt the new input system?

bump
any one has any idea?