How do i reach this room ?

[Hvandiir]

https://imgur.com/a/4jSFkM8 This room is right under prefect bathroom but i dont know any way to reach there.

Edit: Found the entry.

[่่่่]

you need alohomora lvl 3 on one of the doors down and then use glacius on the fireplace

[RPG Gamer Man]

There is one similiar also you need to freeze fireplace in library too that is similiar.