Change position of an object on a keystroke within a trigger only?

Probably a newbie questions but I would like to transform an object’s position on a key input, but only have this work within a particular trigger.

Thank you!

void OnTriggerStay()
{
if (Input.GetKey(KeyCode.A))
{
//change position
}
}

OnTriggerStay() is called most but not all frames so you might want to set a bool to true inside OnTriggerStay() and check for input and the bool inside Update()