Your screenshots show that you likely have Windows core isolation memory integrity enabled. You will need to disable this so ThrottleStop can access the CPU voltage control register. If maximum security is important to you, leave this safety feature enabled and do not use ThrottleStop.
Exit ThrottleStop, delete your ThrottleStop folder and download the latest version of ThrottleStop, version 9.7. There have been quite a few changes and updates to ThrottleStop during the last 6 years.
Post an updated screenshot of the FIVR window after you get core isolation disabled. There are links in my signature that explain how to disable VBS.