You have a double whammy to deal with in a RHD Morgan of course: toll booth will be on the wrong side and the car is too low to reach. The hood up, will make it virtually impossible. Even with a passenger to do the business, she probably won’t be able to reach.
If you think we have problems in Morgans , just consider the plight of even lower vehicles. In 2008 we were bundling down the autoroute to Classic Le Mans (organised by the late and much missed Quentin English) and we came alongside a convoy of GT40s (they were the featured marque that year) . The first car would pull up into the parking area , deposit the passenger who would go to the machine and take out tickets for each of the group as they went through. The passenger then had to distribute all the tickets and regain their car. The whole convey set off again at high (no make that VERY high) speed for the next toll booth. This procedure took the 5 or 6 cars quite a time.
As a result although we were cruising at only 85 mph on our +8 , we were easily able to keep pace with them from the first toll booth on the A26 all the way down to Rouen, and they were cursing at some very high speeds indeed.
I didn't know this but the GT40 was so named because it is 40 inches high!