V4.1 - download the Image from the app

Setup

One Image serves every console - the guest is identical, only the
host binary differs. Copy Image to the root of your SD card, then
the binary for your console:

Console	Binary	Goes to
3DS	3ds/3ds-cli.3dsx	sdmc:/3ds/3ds-cli/
Wii U	wiiu/3ds-cli.wuhb	sd:/wiiu/apps/
Switch	switch/3ds-cli.nro	sdmc:/switch/
Wii	wii/3ds-cli.dol	sd:/apps/3ds-cli/boot.dol
GameCube	gamecube/3ds-cli.dol	SD Gecko / SD2SP2

On the 3DS, Wii U and Switch you can skip the Image step: launch
the app with none on the card and it offers to download this
release's over WiFi.

The Image has the root filesystem bundled in: on first boot the app
unpacks it to rootfs.ext2 on the card, which stays as the writable
disk from then on - changes persist across sessions.
Includes: bash, htop, neofetch, nano, vim, tree, wget, dropbear,
procps, util-linux.