Something like Gtechniq Exo or Halo will add the slickness/water beading/ease of washing to the surface. One thing to note is they don't last as long on PPF as they do on actual paint.
A spray sealant like Gyeon Wetcoat is a decent alternative.
Can't you use both? Then wax polish on top of that?
Well you could, but ceramic coatings in my experience require decon washers, toppers etc etc so I'm just wondering if there is any real advantage to both or just go for a spray on/off solution and save time/effort.
Titan Coatings Apollo TX130 is specifically designed for PPF and wraps and offers amazing chemical resistance and water behaviour. I’ve had it on my last 4 cars PPF and it’s by far and away the best I’ve experienced