There is no payload.bin in iode-4.1-20230401-akari-fastboot.zip ; however, there is one in iode-4.1-20230401-akari.zip : I think you looked in the wrong file.
And: there is no recovery.img, but boot.img, that must be flashed to the boot partition. It contains the kernel and the recovery.
The fastboot flashing method is much easier: you uncompress a zip file, you just need to have fastboot (adb not required), you execute a script, and eveything is done. No need to flash the recovery , to enter it, to sideload… Only samsung devices do not support this method, all other devices do.