I'm certain no spout available for these tanks.
Willk's jiggle syphon will do the job probably lifting fuel from the tank on the floor to the car. I use one go these below which are stupidly cheap, light and apparently flimsy but mine have lasted ten plus years so far and in some circumstances really handy for a spill free transfer...
https://www.jmart.co.uk/products/super-siphon-pump
A funnel with flexy spout, wide mouth and handle would be easy...
https://www.amazon.co.uk/Draper-5614...0001K9WB2&th=1
Worse of all of course from a design perspective the inevitable lemonade bottle as there is no length of spout to go in the car filler, the mouth is narrow to pour into and there is no handle.
Re spill free pouring... be accurate and confident pouring from a 12l tank as indecision will cause loads to run down the tank and not go in the funnel.