Error: self signed certificate in certificate chain

Hi guys,

I’m trying to implement PayU API in my app, and I have not been able to ping:

This is the URL of the API:

So this my code:

I modified the file ionic.project:

"proxies": [
      "path": "/service.cgi",
      "proxyUrl": ""

Then established a constant:

  appPedido.constant('ApiEndpoint', {
    url: 'http://localhost:8100/service.cgi'

In my function I make this call:

 var parameter = JSON.stringify(
          "test": true,
          "language": "en",
          "command": "PING",
          "merchant": {
             "apiLogin": "11959c415b33d0c",
             "apiKey": "6u39nqhq8ftd0hlvnjfs66eh8c"
         url: ApiEndpoint.url,
         method: 'GET',
         params: parameter,
         headers: { 'Content-Type': 'application/json;charset=utf-8' }
     }).then(function (results) {
     }, function(err) {
          console.log('error en la matrix', err);

I have this error:

"Error: self signed certificate in certificate chain
   at Error (native)
   at TLSSocket.<anonymous> (_tls_wrap.js:929:36)
   at TLSSocket.emit (events.js:104:17)
   at TLSSocket._finishInit (_tls_wrap.js:460:8)↵"
“Internal Server Error”

I have the CORS Chrome enabled. Any idea what is going on?