If SATA is what you want instead ... Building a higher-current card, or card+host combination? Technically, M.2 connectors are rated at 0.5 A per pin, so, M-key with its nine 3.3 V pins would ...
The M.2 specification, thankfully ... And, if you have a simple external adapter that has only a PCIe connector or a SATA connector, it will only support that type of SSD. There are two somewhat ...