There is no official "Bloxd.io X-Ray Texture Pack" file you can drag and drop. There are, however, third-party scripts and modified client-side resources that create the effect.
: The game developer (Arthur) frequently updates the engine to block X-ray packs by replacing transparent textures with solid colors like black. bloxd io x ray texture pack url download link
X-Ray packs work by making common blocks like Dirt and Stone transparent while leaving ores visible. How to Install the X-Ray Texture Pack There is no official "Bloxd