scenario for 10 users posting every second for a period of 3 minutes

Could someone help me to setup a scenario.
I want my test to have 10 users posting every second for 3 minutes.

Here is how my scenario and setup are:
val scn = scenario("MQTT publish).exec(publish)

setUp(scn.inject(atOnceUsers(10))).protocols(mqttConf)

Thank you

Probably inject constantUserPerSec(10) during(3 minutes) ?