There is a sign at the beginning of the video that mentions some town in 12(or 23)km distance, and a second one "Donetsk" 103 km. Based on the russian flag on the dashboard i assume he is moving from russia east to west, so 100km driving distance to the east of Donetsk is close to the russian/ukraine border. It's very likely that fuel supplies in that area have been the target of Ukraine attacks, or that the fuel for this gas station has been diverted to the russian army operating in that area instead.

Not sure if this one video here reflects that state of fuel supply in all of russia.