My suggestion is that you write in your intro email or session application . . . I like role playing but I might explore a spanking without a specific role playing, depending on the setting!

A significant number of mistress specifically state on their website or introductory page that they do and enjoy role playing and love it . . . and other do not say that explicitly.

You might also consider writing, "I need to be spanked, but I don't know why! Role playing can be a part of this; you decide."

Most mistresses will work with you either way, I think and most will work with you even if you request role playing verbally at the start of the session . . .

You are simply more likely to get a more complete and passionate role play if the domme knows a few days in advance!