1 TB, PCIe L85370-005 is the part number of the factory 1 TB NVME drive. If you order it from HP it will be much more expensive than retail alternatives and hard to say exactly what they would send you. Likely an OEM Samsung M.2 not likely the 970 Evo Plus.
HP has posted this Service Manual on the home page, which seems to be for a different model but all the specs and such are consistent so apparently also applies to the 15z-eh000 CTO series that you have.
I'm really scared that the Samsung 970 evo nvme will overheat in a laptop... what do you think? There's been lots of words on the internet that nvme drives get really hot, and some fail within a year or so... My old sata ssd 2.5" is running really cool, and I love it. I'm having qualms about this laptop and nvme. Really wished it had the sata port. Do you know if a nvme will be able to boot to windows in an external enclosure?
CTO = Custom to Order. No you cannot boot to an external enclosure. My personal laptop has a Samsung 970 Evo Plus as does the workstation at my office and about 10 other laptops and desktops I have built or set up in the last couple years. NVME perhaps runs a bit hotter than SATA M.2 but not enough to be a concern. If you are really worried get one of the paste-on heatsinks and add it onto the NVME after installation. Your laptop is designed for an NVME M.2 SSD so its configured to deal with any heat issues.
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