Usb Adapter For eMMC card

I know the subject of flashing an os to eMMC cards has been gone over a lot on this forum,but I’m just not getting it. So, to make it simple, is there a eMMC to usb adapter that will work with libre emmcs? I’ve seen plenty on Amazon but all the reviews say they won’t work with Libre emmcs. Any advice would be greatly appreciated. Thanks

eMMC on Renegade will show up as /dev/mmcblk0 when you boot from a MicroSD card (/dev/mmcblk1). You can boot up an OS and then flash /dev/mmcblk0 using whatever flashing tool. We recommend gnome-disks.

There’s no adapter available.

So I am trying to flash libreelec to the emmc. Then I should flash ubuntu or raspberry pi os to an sd card and use that to flash the emmc?