I buy the Blue DEF from Walmart. I found that if you take two of their disposable filler hoses and place then together, they will not leak and gives you the ability to fill without spilling.
Since they're are not filled that often, pull out a stool or something at the same height as the filler spout, rest the container on the stool and then just tip it over to fill. You could even have a shelf swing out from the filler if it's an issue.
Don & Mary
2019 Newmar Dutch Star 4018 (Freightliner)
2019 Ford Raptor