Create a Look action with:

Action Type: Value
Control Type: Vector2

Typical bindings:

• Mouse Delta
• Gamepad Right Stick

Read it:

Vector2 look =
    lookAction.action.ReadValue<Vector2>();

yaw += look.x * sensitivity;
pitch -= look.y * sensitivity;

Clamp vertical rotation:

pitch =
    Mathf.Clamp(
        pitch,
        minPitch,
        maxPitch
    );