There is a zap split on Nostrudel, if you post a note you can add "more options", enter the npub there, enter the percentage you want to split and press add, it won't respect it always though...🤷🏽♀️
Ya, I phrased my question wrong I guess. I meant to have that functionality for my own client I'm developing. I meant it as a dev question for my client I'm developing, where as far as I'm aware, an LN node is required to set that up, to have Zap Split functionality, unless my knowledge of that is wrong / there is a way to do it without it.