After opening the app, it lists contents, warnings, cautions and careful usage. I don't see anything else.
I'm just looking at the sd card again, it seems like that file is already in there :s
From
https://3ds.guide/installing-arm9loaderhax
(Look there for links to files)
You don't need to do the whole thing, but only these
What you need
The latest release of Luma3DS (the .7z file)
The latest release of GodMode9
The latest release of Luma3DS Updater
The latest release of FBI
Instructions
Section I - Prep Work
Insert your SD card into your computer
Copy lumaupdater.cia from the Luma3DS Updater .zip to the /cias/ folder on your SD card
Copy FBI.cia from the FBI .zip to the /cias/ folder on your SD card
Copy arm9loaderhax.bin from the Luma3DS .7z to the root of your SD card, overwrite existing files
Copy GodMode9.bin from the GodMode9 .zip to the /luma/payloads/ folder on your SD card
Section III - Configuring Luma3DS
Boot your device while holding (Select) to enter the Luma3DS configuration menu
Make sure to start holding the button before pressing power
Use the (A) button and the D-Pad to turn on the following:
“Autoboot SysNAND”
“Use SysNAND FIRM if booting with R”
“Show NAND or user string in System Settings”
Press (Start) to save and reboot
Section V - Injecting FBI
Reboot holding (Start) during boot to launch the Luma3DS chainloader menu
Launch GodMode9 by pressing (A)
Navigate to SDCARD -> cias
Press (A) on FBI.cia to select it, then select “CIA image options…”, then select “Mount image to drive”
Press (A) on the .app file, then select “NCCH image options”, then select “Inject to H&S”
Press (A) to unlock SysNAND (lvl1) writing, then input the key combo given
Press (A) to continue
Press (Start) to reboot your device
Section VI - Installing CIAs
Launch Health and Safety (which is now FBI)
Navigate to SD -> cias
Install FBI and Luma3ds updater
Press (Home) to exit FBI
Section VII - Restore Health and Safety
Reboot holding (Start) during boot to launch the Luma3DS chainloader menu
Launch GodMode9 by pressing (A)
Press (Home) to bring up the action menu
Select “More…”
Select “Restore H&S”
Press (A) to unlock SysNAND (lvl1) writing, then input the key combo given
Section VIII - CTRNAND Luma3DS
Navigate to SDCARD
Press (Y) on arm9loaderhax.bin to copy it
Press (B) to return to the main menu
Navigate to SYSNAND CTRNAND
Press (Y) to paste arm9loaderhax.bin
Select “Copy path(s)”
Press (B) to return to the main menu
Hold (R) and press (B) at the same time to eject your SD card
Remove your SD card from your device
Press (Start) to reboot your device with your SD card removed
Booting your device at least once with your SD card removed will allow you to configure the CTRNAND based Luma3DS installation
Use the (A) button and the D-Pad to turn on the following:
“Show NAND or user string in System Settings”
Reinsert your SD card into your device
Press (Start) to save and reboot
This will update Luma, install FBI and Luma Updater (so you can update Luma with only your 3ds in the future) and copy the new Luma version to ctrnand to make your 3ds able to boot without sd.