Truck stops usually do not have gasoline at their truck pumps and only have diesel and DEF. Some like Flying J have dedicated RV lanes but it seems most of the Pilot/Flying J (PFJ) truck stops do not. You may be able to maneuver enough at an outside pump and still get out.
The Next Exit book also has an app, IEXIT which is much easier to use than the book and will update without having to buy a new book.
We have a diesel truck but the stock tank is ridiculously small so we replaced it with a much bigger OEM tank so we never have to fuel on a travel day.