I’d argue it isn’t left or right, just a tool. Leftism isn’t simply redistribution of wealth, but collective ownership of industry. Capitalists can use UBI as a way to replace more comprehensive safety nets, like single payer Healthcare, and implement a flat tax across the board.
You can use UBI as a leftist, to allow everyone to gain the profits of automation and increased productivity, or you can use it as an excuse to cut safety nets. Depends on how you use it!