Passing input parameters from External System

How can I send input parameters to a REST service built in SnapLogic?

We have specified the query parameters in the REST Get snap but can’t see that this being exposed on the API Schema (using the Open API on Projects folder > Select Triggered Task > Download as JSON). This is completely new to me so trying to find my bearings!

{
  "swagger": "2.0",
  "info": {
    "title": "XXXXXXX",
    "description": "",
    "version": "1.0"
  },
  "host": "elastic.snaplogic.com",
  "basePath": "/api/1/rest/slsched/feed/XXX-Dev/XXXX/XXXXXXXXX",
  "schemes": [
    "https"
  ],
  "paths": {
    "/XXXXXXXXXXXXXX": {
      "get": {
        "produces": [],
        "responses": {
          "200": {
            "description": "OK"
          }
        }
      }
    }
  },
  "securityDefinitions": {
    "basicAuth": {
      "type": "basic"
    }
  },
  "security": [
    {
      "basicAuth": []
    }
  ]
}