Securely pass credentials in JSON Body

With the API I am using, I need to pass credentials though JSON in the body of the request.

{
“username”: “admin”,
“password”: “password”,
}
image

Is there a way to reference the credentials set up in the “HTTP Requests” in the workflow?
workflow

If you don’t mind everyone having the ability to see them, you can save them as parameters in the workflow.

Configure Workflow Parameters | InsightConnect Documentation (rapid7.com)