I want to upgrade a macbook air from 2015. I have done lots of drive replacements (and watched the videos for macbook air) but I'm not sure what form factor and connection specs to search for on amazon or newegg. I think that these computers use a PCI-E 3.1x4, but am unsure what form factor drives will fit in the tiny case. I'm also concerned about what connectors the computer uses. I'd hate to get one that needed an adapter. It's my understanding that NVME drives would need some kind of adapter.
Can anyone provide the specific connector and form factor details?