What type of anchor should I use for ceiling hook for ceiling fan

It appears to my eye to be installed entirely correctly. To be sure, try to hang a fairly significant amount of weight (about 2x to 3x the weight of the ceiling fan) on that loop and see if the anchors hold. That multiple of the ceiling fan weight is your "safety factor". Use a cheap weight for that - maybe a plastic bucket filled with books. You'd much rather accidentally drop a bucket full of books while you're watching it than drop the expensive ceiling fan on some little kid's head while it's running at high speed.

This is a masonry ceiling? Those anchors are only suitable for masonry, never for drywall.

With stucco the wall is two thin for tapcon screws, Since you already have a hole I think your best bet is a molly bolt or toggle that expands once inside the wall fill the hole with calking so no moisture or bugs can find thier way in.