Paying for a UBI is the easy part. What most people (including economists) aren't aware of is that new money is created every time the Federal Government spends. That money is then destroyed when it returns to the Government through taxes, fines, license fees, etc.

They can create as much money as they want, but they really ought to limit themselves to only creating enough so that everything that's for sale can be bought at current prices. If they create too much money, then prices will go up and you could have hyper-inflation.

I don't know what the figure is in the US, but in Australia, the Government could give everyone $3-3.5K without having to increase taxes. If they were to give more than that, they'd have to increase taxation. When I say that to UBI advocates, they complain that $3.5K isn't enough to help anyone. When I point out that jobs could be created for every unemployed person at ten times that amount instead of going for a UBI, they still want the UBI.

Would everyone become lazy and do nothing? Absolutely not! The money would be sucked up by toll collectors before they had a chance to relax. They'd have no choice but to keep working to earn more money which will also be sucked up.