Gatling Jason Parameter Substitution Issue

Hi Guys

I got following Jason body in my request. I have captured value for event_token in eventToken parameter and substituting this as per below in Jason body

.body(StringBody(session =>

s"""

{

“event”: {

“id”: “CREATE”,

“summary”: “4th Page Check your answers - Event summary 9999999”,

“description”: “4th Page Check your answers - Event description 9999999

},“event_token”: “”"" + “${eventToken}” + “”"",

“ignore_warning”: false

}

“”".stripMargin)).asJSON

for some reason it’s not substitution value so my request is keeps failing so I guess I am not doing in correct way.

See below the log from gatling

stringData=
             {

             >  "event": {
             >    "id": "CREATE",
             >    "summary": "4th Page Check your answers - Event summary **9999999**",
             >    "description": "4th Page Check your answers - Event description **9999999**"
 **|  },"event_token": "${eventToken}",**
  "ignore_warning": false
}

Please suggest how to fix this issue