Depends. You can use mattys prebuild uf2 files with modified Hekate, or you can flash it your self with any payload you want using arduino.
I can also recommend this tool here, which gets WAAAAAAAY too little attention.
https://gbatemp.net/threads/samd-fusee-payload-launcher-v2.517731/page-4#post-8280815
Connect your modchip in flashing mode to your PC -> take the CURRENT.UF2 file and paste in the folder of UF2-Splicer -> take your desired "payload.bin" -> let the UF2-Splicer do it's magic and flash the new CURRENT.UF2 to your mochips.
Easy to use and no messing with Arduino etc.
Last edited by FR0ZN,