On PRT you cant adjust what prices you see so they are all Mid prices .so if using their chart you have to account for the spread.
So for example if trading Dax the spread is 1.2 .If you see the high of the day is 12000 and want to go long at that price you have to enter 12000.6 which is half the spread.
So basically you have to add half the spread to orders .Its easier if what your trading is fixed spread its always the same,But if you are trading something with variable spreads its harder to account for it.