One of ingredients that differentiates Coquito from traditional eggnog is the addition of coconut cream milk. Now this is another ingredient that can differ for various Coquito recipes. Instead of coconut cream milk some recipes might call for natural coconut milk, or cream of coconut.
Some people tend to use fresh coconut milk instead of canned. In preparing Coquito the coconut milk is simmered with evaporated milk and other ingredients as as desired or if a recipe calls for them specifically. The coconut milk is then strained, cooled, and is then combined with the rest of ingredients.
Another alternative is using Cream of coconut which is essentially coconut cream that has been sweetened.
This is just the basic process gathered from reading different Coquito recipes, so follow the procedures outlined in the recipe you are following specifically. Personal preference for coconut tends to vary among people so some may vary the amount of coconut milk if you’re preparing it for someone who likes either a little or a lot of coconut flavoring.