Special House?

Hey, so again I want to make an area a Pokémon’s house without knowing what’s missing.

Manaphy is a top tier Pokémon of mine, I have such fond memories of it, I got Rangers before the code for their mission came out, me and my friend theorized how to get the mission so we could have the egg when gen 4 came out, then worked to allowed to in school, a Manaphy plush was one of my mainstay plushies (I still have them all just not in front of me like I used to).

Manaphy deserves a super special house, which of course means the ocean temple, but what the heck is missing!

I filled in the areas to the side with moss blocks, but it still isn’t available, is it to big? Do I need to add walls or something?

I want Manaphy to have a home they deserve, but I don’t know what needs to be done for that.

TL;DR I really like Manaphy what needs to be done so I can give them the ocean temple to live in, instead of seeing, “No home,” whenever I check status?