If you are searching for you are likely looking for one of two things: either the proprietary system files required to boot Switch games (firmware) or the final archived versions of the emulator itself.
These are popular tools found on GitHub that allow you to export your system's Registered firmware folder to your SD card. yuzu emulator firmware download github
Are you using the or one of the new forks like Suyu? If you are searching for you are likely
– Tools that help you extract firmware from your own legitimate Switch dump. – Example: switch-firmware-tools (not hosting firmware, just parsing/extraction logic). just parsing/extraction logic).