Replace failed HD in Mac Formatted R-Aid with Thunderbolt

I have received the replacement 8TB drive for my Raid 1 system. I need help installing it. I have the G-Raid Thunderbolt Configurator. I have placed the replacement drive in the case. The red light is on at the front of the case and the replacement drive shows a red light (I am not sure whether the failed drive as at the top or bottom- I have inserted the replacement at the top).
I have found the article “How do I rebuild the RAID on my G-RAID w/ Thunderbolt 2/3?” but when I load the configurator it cannot find any device.