They can stay closed for quite some time when newly introduced. It looks fine.
Get it up off the sand and onto a rock. It will probably shed.
Looks to be attached to a small piece of rubble, so glue the rubble to the rock to hold in place.
It will want medium to low light and low to medium flow. These guys do not want or need much.
If unhappy, it will drop babies and if dying it will slough away.
They like some nitrates in the tank.
Good luck.