There is no UBI without MMT. The issue with UBI is not "paying for it" but, rather, servicing it. We can't give everyone a certificate good for one unicorn. Why, then, can we give them certificates for food and and shelter? We need to figure out how to create the food and shelter first. If we do that, finding a way to give people access to them is simple.

UBI is an advanced technology of demand; it requires an offsetting advance in the technology of production. Of course, if we already have the latter, we just need to bring it bear, in which case printing money to fund the purchase of the increased outputs would not be inflationary, i.e., there would be no need for revenues to fund it.