Clownfish wont go into anemone?

You know why these evolved damsels use anemones?
For protection from predators or other nasty fish or invert species, where are the predators as such to these guys in your tank making a necessity to use it for protection?

To reproduce the mucus coating on anemones once they consume some to mimic it. so the anemone doesn’t know the clown fish is there, It takes energy with in them via certain organs to recreate and then excrete once copied, so many don’t bother going to that effort to do this for a short while or a long time!

If your clown fish starts hosting an actual coral species instead of the anemone you provide in your tank, this can shorten their life span considerably!
You see the coral will sting as do anemones and the clown will have to copy the coating on the coral but all corals coatings are slightly toxic to them and will eventually poison/shorten the life of the clown fish!

When they do start using the anemone, it could be a territorial thing, the time to act adult is there or even you putting your hand in the tank may inspire them to start using an anemone!
They will most likely, either straight away or in a year, or when ever use the anemone, but if they don’t need the anemone, then its up to them.