CORS problem from my local to Iris server with a REST API

I built my rest api with ^%REST and update with CreateApplication.
Postman works fine and I suppose production server will work fine as UI and rest api will be on the same domain, but for now in dev, I need to have access from my local to the Iris rest api. I have a CORS error.

I do not know how to configure my swagger file to have either Parameter HandleCorsRequest=1 or <route Cors=true in the generated displ,cls.

As adviced in community, I tried in my impl.cls
    Do ..%SetHeader("Access-Control-Allow-Origin", "*")
I even tried 
     Do ..%SetHeader("Access-Control-Allow-Headers", "*") // Content-Type,X-Amz-Date,Authorization,X-Api-Key
    Do ..%SetHeader("Access-Control-Allow-Methods", "*")
No success

Do I need to set the headers in my swagger file? It is not very elegant....
    responses:
            statusCode: "200"
            responseParameters:
              method.response.header.Access-Control-Allow-Headers : "'Content-Type,X-Amz-Date,Authorization,X-Api-Key'"
              method.response.header.Access-Control-Allow-Methods : "'*'"
              method.response.header.Access-Control-Allow-Origin : "'*'"

Do I need to have my own copy of disp.cls?

Do you have an elegant solution to manage dev and production to do the switch cors or not cors?

Thank you.