Can't print WMS in MapFish

Question

I am trying to set up a template in jasper reports to send to MapFish print. I am specifying the map layers in the requestData.json file. I am testing with a single layer, and have tried map services both inside and outside of my network. No matter what services I try to load, I keep getting this error:

Exception in thread "main" java.util.concurrent.ExecutionException: java.lang.IllegalArgumentException: java.lang.IllegalArgumentException: java.lang.IllegalArgumentException:

followed by the service call, in this case it is:

Exception in thread "main" java.util.concurrent.ExecutionException: java.lang.IllegalArgumentException: java.lang.IllegalArgumentException: java.lang.IllegalArgumentException: https://www.fws.gov/wetlands/arcgis/services/Wetlands/MapServer/WMSServer?SERVICE=WMS&LAYERS=1&FORMAT=image%2Fpng&HEIGHT=683&REQUEST=GetMap&WIDTH=749&BBOX=-97.85928104890104,39.068060413061325,-97.55349673109896,39.28509312021114&STYLES=&SRS=EPSG:4326&VERSION=1.1.1 is denied.

I have started with the json and yaml files for the verbose example given in the MapFish git hub page https://github.com/mapfish/mapfish-print/tree/master/examples/src/test/resources/examples/verboseExample. Here is my requestData.json:

{
  "layout": "11x17 landscape",
  "outputFormat": "pdf",
  "attributes": {
    "number": 45,
    "length": 45.123,
    "table": {
      "columns": ["id", "name", "icon"],
      "data": [
        [1, "blah", "icon_pan"],
        [2, "blip", "icon_zoomin"]
      ]
    },
    "datasource": [
      {
        "displayName": "Feature 1",
        "table" : {
          "columns": ["id", "name", "icon"],
          "data": [
            [1, "blah", "icon_pan"],
            [2, "blip", "icon_zoomin"]
          ]
        }
      },
      {
        "displayName": "Feature 2",
        "table": {
          "columns": ["id", "name", "icon"],
          "data": [
            [10, "blah2", "icon_pan2"],
            [20, "blip2", "icon_zoomin2"]
          ]
        }
      }
    ],
    "legend": {
      "name": "",
       "classes": [{
        "name": "Arbres",
        "icons": ["http://localhost:8080/examples/data/www/legends/arbres.png"]
      }, {
        "name": "Peturbations",
        "icons": ["http://localhost:8080/examples/data/www/legends/perturbations.png"]
      }, {
        "name": "Points de vente",
        "icons": ["http://localhost:8080/examples/data/www/legends/points-de-vente.png"]
      }, {
        "name": "Stationement",
        "icons": ["http://localhost:8080/examples/data/www/legends/stationement.png"]
      }]
    },
    "map": {
      "longitudeFirst": true,
      "center": [-97.70638889, 39.17657778],
      "scale": 100000,
      "projection": "EPSG:4326",
      "dpi": 72,
      "rotation": 0,
      "layers": [
      {
        type: "WMS",
        "layers": [1],
        "baseURL":   "https://www.fws.gov/wetlands/arcgis/services/Wetlands/MapServer/WMSServer?",
        "imageFormat": "image/png",
          "customParams": {
          }
        }

      ]
    }
  }
}

and here is my config.yaml:

pdfConfig: !pdfConfig
  compressed: false
  author: "Mapfish Print"
  subject: "Mapfish Print Verbose example"
  creator: "Mapfish Print"

throwErrorOnExtraParameters: true
templates:
  11x17 landscape: !template
    pdfConfig: !pdfConfig
      title: "Verbose 11x17 landscape"
      keywords: ["legend", "table", "tablelist", "map", "verbose"]
    reportTemplate: simpleReport.jrxml
    attributes:
      number: !integer {}
      length: !float {}
      map: !map
        maxDpi: 400
        dpiSuggestions: [72, 91, 128, 254, 300, 400]
        width: 749
        height: 683
      legend: !legend {}
      table: !table {}
      datasource: !datasource
        attributes:
          displayName: !string {}
          table: !table {}
      scalebar: !scalebar
        width: 150
        height: 40
    processors:
    - !restrictUris
      matchers:
        - !localMatch
          port : 8080
          pathRegex : /.+
    - !reportBuilder # compile all reports in current directory
      directory: '.'
    - !createMap {}
    - !createScalebar {}
    - !prepareLegend # create a datasource for the report with the 'legend' attribute
      template: legend.jrxml
    - !prepareTable {}
    - !createDataSource
      reportTemplate: table.jrxml
      reportKey: reportTemplate
      processors:
        - !prepareTable {}
    tableData: jrDataSource

I am using the MapFish command line tool to generate the print file, version 3.18.2. Can anyone help?