apparently it had to be done:

export GEO=9q; echo '{"content":"pow pow powerbot, pow pow powerbot, powerbot! pow 21!"}' | nak event -k 20000 --tag g=$GEO --tag n=powbot | ./nip13_miner 21 | nak event $(./geohash_relay_finder -q $GEO relays.csv)

https://github.com/ynniv/nip13_miner