으면 만들다

if there isn't one, make one

A conditional "-(으)면" plus 만들다 "make". The commonest shape here is the can-do line built on 없으면: there's no seat, so just make one; if there isn't one I'll have to make it; if there's something I need I make it. Others set a requirement instead — you can't make it unless you actually sit at the desk and work, if this country were normal they'd have made it. It is the everyday frame for "make it yourself if it doesn't exist".