Tracking eCommerce: ec_items problems

Newbie alert!

I’ve been banging my head against the proverbial wall, to try to get the server recognize my tracking request using the curl line below, but to no avail. I can’t seem to get the ec_items correct!!
Please help!

curl -i -X POST -d '{"requests":["?idsite=1&url=https://foobar.com/cart&action_name=FOOBARBAZ&_id=8973&apiv=1&idgoal=0&rec=1&ec_id=123&ec_items={"1":[3533,"Piyo Piyo","Babyware",15,"1"],"2":[4743,"Cleansing Gel 50g","Beauty",5.88,"1"]}&revenue=9311.43&ec_st=113&ec_tx=7&ec_sh=7.5&ec_dt=5.4&_ects=1512057600"]}' https://barbaz.com/piwik.php

I’m getting: {“status”:“success”,“tracked”:0,“invalid”:0}