Hi and thanks for the question.

If those logs are the vented kind, you can buy a conversion kit for them. A conversion kit usually consists of a valve regulator, pilot orfice and burner orfice(s).

If the logs are non-vented you're out of luck. No vent-free product can be converted. If it were a fireplace system you'd have to replace the burner unit. Since that's all you have you might as well sell that and start over.