So make a new file in photoshop like this…
now create whatever it is that you want, make sure it’s centred in the square then duplicate the layer
now go to filter>other>offset
set the offset to half of the width and height of the box and select the “Wrap around” thingy
save as a png and then apply as your background
hope that was helpful!
You can ask me anything and I’ll answer honestly, but only with yes and no.