It says you have to get Solgaleo in Moon by "evolving Cosmog/Cosmoem" when the evolution chart says you can level up Cosmoem to evolve to Solgaleo IN POKEMON SUN! It's the same thing for Lunala. HELP
The only way to get Solgaleo in Moon is by getting a Solgaleo through a trade. Cosmoem will never evolve into Solgaleo in Pokemon Moon and vice versa with Lunala in Pokemon Sun.