I can’t comment on QNAS compatibility. However, some information that i found missing in the product description is as follows.
The card has two slots, one for m.2 PCIe NVME storage and another for m.2 SATA NGFF storage. The NVME storage would use the PCIe slot on your mainboard for power and data. The m.2 SATA would use the PCIe on your motherboard for power, however for data it has a SATA connector which needs to be connected via cable to an open SATA connector on your motherboard. You can’t use 2 m.2 SATA storages.

Unfortunately I can't give you an answer. It depends on your mainboard. But it is normally in the description of the product.