How to launch and control writing with multiple open zones when testing F2FS on ZNS SSD by FIO?

[bpan2020]

How can I launch and control multiple open zones when testing F2FS on ZNS SSD by FIO?
How can I enable F2FS to utilize more open zones for writing operations? Even when I use 32 jobs to write 32 files, the write performance appears to be similar to writing with only one open zone.

for i in {1..32}; do fio --filename=${mountpoint}/f2fs_${i} --size=4g --ioengine=libaio --bs=128k --iodepth=128 --rw=write --name=job_${i} & done