VGC has the following sales figures:
HW WiiU: 1.26 million
HW 3DS: 0.49 million
HW Switch: 0.46 million
As VGC stopped tracking sales 2019, the Switch-sales may be a bit higher by now, how much is hard to guess. I don't know any shipment figures.
The WiiU version managed 1 million shipped.
The others there's no shipment nor any CESA data for them. That means they're definitely < 1 million.