sys-ftpd-light VS aio-switch-updater

Try https://github.com/cathery/sys-ftpd-light. It's super convenient.

I recommend sys-ftpd lite (which runs in the background), https://github.com/cathery/sys-ftpd-light you need to edit the config.ini located in config/sys-ftpd/config.ini you can configure the user/pass or just enable anonymous:=0 then you can use a client like filezilla, winscp or windows ftp to access your switchs sd card with your switchip:5000 u/ToxiClay you should try this too.

yes you can use FTP, either https://github.com/mtheall/ftpd or https://github.com/cathery/sys-ftpd-light, you still need to transfer your files prior, also you can mount your switch via usbc cable using tegragui, I also believe there's a homebrew app that allows you to access the microsd card via usb cable https://github.com/retronx-team/mtp-server-nx i think

tried to make sys-ftpd-light function, but it still won't.

Have you checked AIO? There is a good chance that FW its already there.

You can also grab it from their GitHub, you should be able to get some info there

put this on sd https://github.com/HamletDuFromage/aio-switch-updater update

Now as for the 2nd section you can just get the official firmware through AIO updater. After getting the OFW just follow the third section and you should be good to go.

Use AIO Updater