Simple HotSpot Voucher

Yes, I ran the commands. I set the write permission, selected the 3rd entry option and uploaded the voucher.txt.

I found it in the description. Question: in my case, what should I change it to? radio0.network1?

Trial and error?
Works for most people...

Your guest configuration is entirely wrong. It even says so in the image you posted - ie "Error: Network device is not present".

You will find many explantions of how to set up a guest network on this forum and elsewhere.
But as I said, you will get help with the voucher script on Github.