Create a Material with your custom JPG as the Texture -- scale the Texture to the size of the wall -- assign this material to the face of your wall -- you may have to adjust the origin of the Texture, in which case from within the 3D window, goto Design > Align 3D Texture > Set Origin, and click one of the bottom nodes of your wall.
MacBook Pro Apple M2 Max, 96 GB of RAM
AC26 US (5002) on Mac OS Ventura 13.5