It doesn't follow that we will be able to do it, nor even that it is possible, but before the understanding that flat universes contain zero energy, the claim that you might manufacture a universe would seem to completely absurd. Where would you get all that energy? Especially if energy is conserved?

As it turns out, it doesn't matter if energy is conserved, because a flat universe doesn't have any net energy, and consequently they can come into existence without violating known conservation laws.

In any case, you don't have to take my word for it. Look up Alan Guth, the MIT cosmologist who invented the inflationary universe theory. This is his claim.