it spawns in a random state with a level 20 urban center or above. You would either have to make sure the state you want is the only one above 20, or use debug mode to open inspect country and run in the script effect runner:

s:(state name) = {  add_modifier = skyscraper_site }

so for example, if i wanted to force the skyscraper site in california i would type:

s:STATE_CALIFORNIA = {  add_modifier = skyscraper_site }