we don't have a recovery partition. that's you flashed twrp to the boot partition, right?
and when you flashed the ROM - boot from the ROM replaced twrp.
you needed in twrp
flash ROM. and immediately without rebooting into twrp-Advanced-Flash in ramdisk. somehow, and somehow in both slots. so that twrp flashes itself again.
ps: and I would not advise flashing twrp permanently. you can lose all data at once. after the next update, the ROM may not boot if you forget to flash the twrp again. and you will have to look for a computer to flash twrp