The locksmith said my Car has no key code

I've contacted two locksmiths to come and look at my car
because we lost the fob key and wanted to reprogram. Both
said when trying to get the key code to program the key
that there was no key code and that there was no way of
programming a key, but it might be a technical issue that
they didn't know about. When I tried turning the spare key in
the ignition they key goes all the way through without the
car making any noise or effort to start. Is there a way to fix
it? A battery problem?