How do I attach a hand to a spot using Inverse Kinematics and keep it there even when the body moves?

I am trying to make a climbing game like A difficult game about climbing and New heights where you control the hands of the character to climb up. I am new to using Inverse kinematics but I managed to control the hands of my character using the FastIK asset, however I can’t manage to make the hands stay attached to a spot when the body moves. For example, I want the character’s left hand to grab a spot and stay attached to that spot while climbing, even when I move the rest of the body to make the right hand grab another spot. Is it possible to achieve this using IK, if so how can I do it?

Perhaps your IKGoal is set to a relative position? If the Goal is in global coordinates, it should be fixed. IK is essentially a post-processing step that occurs after the body has moved.