Looks like that’s actually “SATA Express,” which has lanes for both PCI and SATA - if you look at the other side of the connector (which you should have already shared!) you’ll see even more contacts. You can get either a PCI or SATA adapter in order to use the drive.
Edit: Probably SAS as others said. It uses the exact same connector, which is why I made that guess.
Can you show us the other side of the drive? Curious what make/model this is supposed to be. Best guess is that this is yet another attempt by a PC manufacturer to sell un-upgradeable units that need to be either replaced as a whole, services only by then, or had at with wire snips and a soldering iron.
I’d say it’s time to carefully cut out that tab (leaving the keys intact), and to start being more careful about what you buy.