Thank you so much for reviewing my game!
Actually once you collect the fuel, you have to hover your cursor over the van's fuel cap, and it should prompt you allowing you to refill it. That should help with the progress.
Also a quick heads up, there is a rare bug where the narrator's final voice lines might not trigger even after you complete all the tasks. It usually works perfectly, but I wanted to mention it just in case.
Thanks again for your time and feedback, and I hope you enjoy the rest of your playthrough!