Would like to help but not enough info really. No clue what kubikos is. In general, I'd select the existing level to find its world position. Maybe move the existing level so the floor top is at 0,0,0?
Viewing post in Using MAST in existing scene
KUBIKOS is just a cube world asset on asset store, looks a bit like roblox. I went ahead and moved my scene around some more until i got the grid lines to appear at the base level of my ground. but i had to figure out how to make the MAST grid larger, I figured it out in the settings so it covers my whole world. thanks for the help, i got it now.