can't connect a keyboard to my old mac mini (2007)

I'm trying to get my old mac mini restarted because it has some software on it that I lost when I updated my new mac to Catalina. The old computer starts, the OS loads, I get a login screen. I have connected a wired mouse because it says it can't find a wireless mouse. But it still can't find a keyboard. I have an old wired keyboard but it doesn't recognize it. I also have a wireless keyboard but it doesn't see it and asks me to make sure it is discoverable. I don't have any of the documentation for the mini, so I don't know how to proceed. any wisdom would be much appreciated. BTW, the device I chose is wrong, but there is no way to specify an ancient mac mini).