I was getting gas in my 94 ford ranger EXTCAB and gas was pouring out under truck?

How do I see if its the fuel neck? I used a tiny auto camera to stick all the way down the gas neck and didn't see any holes

There's a rubber 'gasket' that fits onto the gas tank, then the filler pipe slides into this gasket, to seal the fuel tank. They do dry-out & come apart sometimes. Not that much work to remove the filler pipe from the truck & put a new gasket on the tank. Put some grease on the filler pipe so it will slide back into the gasket.

You SHOULD be able to get down under the truck and see most of your fuel filler neck. (Make sure the truck is in park with the brakes set.)