Boot9.bin «RECOMMENDED – ANTHOLOGY»

: Different versions of boot9.bin may be required for various homebrew applications or system firmware levels, necessitating careful version management.

You cannot dump boot9.bin without already having boot9strap or another exploit that gives ARM9 access. Follow the official (https://3ds.hacks.guide) to install boot9strap first — the process will automatically dump boot9.bin for you. boot9.bin