I am trying to add an additional LUKS encrypted password to our work PC so I do not have to the admin password. However, when I try it says that the device is not a valid LUKS device.

The PC is using RHEL 8.8 and I currently have two Samsung 512 GB NVME SSDs that I have put a RAID1 one configuration on. I have a dummy PC that I practiced on and I was able to get the additional encrypted password on that one just not the ones we are using for testing. I've made sure to use the correct designation to be encrypted, same as with the dummy PC.

The command I used was:

cryptsetup LuksAddKey /dev/md/RHEL_RAID1p3

I know the original command is along the lines of using /dev/sdb3, but since this is RAIDed its slightly different. Also, this is the exact same command I used on the dummy PC and it was happy. The dummy PC has the exact same hardware and configurations, minus a program or two, but RAID wise it was done the exact same way.

Can anyone help offer a possible explanation why this may not be working?