Worked perfectly. For anyone else's reference, download the Edge Gateway Package from the Codesys Shop, then install it in the Codesys Software. Restart the software, and you will see an option under the Tools Menu for "Update Edge Gateway" Push this out to the PI the same way as you would for "Update Raspberry Pi" using the armfh version of the package, then add that gateway to the comms settings, then you can license the runtime on the Pi.
I have a license key for the Raspberry PI Runtime, and a program set up and running on the PI, but I can't get it to show up under the License manager when I scan the network, or enter the device address. I've tried while online, offline, IP Address, device name, and device address. Any help would be appreciated!