I wonder if you could get a plumber to fit a gas tap onto your house gas line, so you could gas your natural-gas car up at home off of your house supply. I’ll bet that would be cheaper than going to a gas station. Shouldn’t be any more dangerous than turning on a gas fireplace. Of course this would probably not be permitted. . .
You need a compressor. And don’t use an air compressor. It needs to be rated for hazardous material. They typically compress into the vehicle tanks 3,000 psi or greater.
Those systems are already available.