Welcome to R2R.
Unfortunately there are no reef safe cures for Marine Whitespot (Cryptocaryon irritans).
There are some approaches that *May* help the fish deal with a light infection, although the parasite will always be in the tank and could spring back wiping out stock (and even then it's very dubious).
The way to cure ciliate parasites (Marine whitespot, velvet, brook etc) is by treating in a hospital tank with either copper or chloroquine (the latter is far more effective IME across all of the ciliate parasite species) and leave the display tank fallow (without fish) for 74 days.
This ensures that the fish are not carrying the parasite and no parasites survive in the display, at any lifecycle stage, to reinfect the stock.
There's often talk of marinading your fish in all sorts of herbs and spices and other such mumbo-jumbo, but none of it actually works and is based on pseudo-science.
Other treatments are either based on Chloroquine ingestion (Ickguard) which is difficult to administer in an effective/measured way and will kill any inverts which eat the food or Hydrogen Peroxide (either neat or in the form of Polylab Medic). Having tried huge and prolonged doses, I can personally attest to it's ineffectiveness as a cure.
The best thing you can do right now is to have a read of posts by
@Humblefish,
@melypr1985 et al on the Fish Diseases subforum and set up a hospital tank:
https://www.reef2reef.com/forums/fish-disease-treatment-and-diagnosis.771/
Hope this helps