How to passing json parameters for test api (restful) in katalon studio?

I create a demo test using reqres.in fake data api I want to create a user with a name and a job parameter, but the data format required is json.

In my katalon test i try do that in the script tab :

My paramaters are not send to the api...

I didn't found how do that in katalon studio (5.7) and i don't know if it's possible to do that.