There are adaptors available, try searching for "NGFF M.2 B + M Key to mSATA Mini PCI-E SATA 3.0 SSD Male Converter Card Adapter" on ebay, the first result for £3.99 should be one that has an m2 "B+M" key connector (with the two slots cut out), is the type of adaptor you want. Most of the adaptors go the other way, letting you plug an m2 into a msata connector, so ignore those ones.
The manual for that particular NUC just says 2 x m2 2242/80, so it sounds like it has two full size m2 slots. But, it doesn't say if they both support SATA drives. This adaptor will fit, but won't work in the m2 nvme only slots. It does say it supports m2 SATA drives though, without any other details, so it sounds like it should work in either slot for this one. The biggest issue is probably space, I'm not sure there would be enough clearance width wise around the slots to fit the drive in, I can't really tell from pictures, but I suppose for £4 it's not the biggest risk if it doesn't fit.