I found a website, 3DHacks Guide, that promised to walk me through the steps of installing custom firmware on my 3DS. I found an SD card adapter that would let me put the SD card into my Thunderbolt dock on my MacBook Air M5, and went through the steps on the site. This method of installing custom firmware asks you to go to a specific website on your 3DS via the built-in web browser. However, installing full custom firmware (what I did)unlocks broader functionality, such as running fan-translated games, emulating retro systems (NES, SNES, GBA), playing custom game mods, and installing custom programs directly to the console. My Nintendo New 3DS XL is genuinely interesting againNow I pick up my 3DS way more than my Switch, because it has a whole bunch of new things I can do with it.