symp_gist.js

fetch("https:.....", { // url used is QA endpoint supplied (excluded here for security reasons)
        method: "GET",
        headers: {
            "Authorization": "Basic c3ltcGxlY3RpY1BTWUNISUFUUlk6YnJpZ2h0Ymx1ZXN0YWdl" //encoded username:password
        }
  }).then(
    function(response) {
      if (response.status !== 200) {
        console.log('Looks like there was a problem. Status Code: ' +
          response.status);
        return;
      }

      // Examine the text in the response
      response.json().then(function(data) {
        console.log(data);
      });
    }
  )
  .catch(function(err) {
    console.log('Fetch Error :-S', err);
  });

symp_gist.php

$URL='https:....'; // url used is QA endpoint supplied (excluded here for security reasons)

$headers = array(
    'Authorization: Basic c3ltcGxlY3RpY1BTWUNISUFUUlk6YnJpZ2h0Ymx1ZXN0YWdl' //encoded username:password
);			
$ch = curl_init();
curl_setopt($ch, CURLOPT_HTTPHEADER, $headers);
curl_setopt($ch, CURLOPT_URL,$URL);
curl_setopt($ch, CURLOPT_TIMEOUT, 60); //timeout after 30 seconds
curl_setopt($ch, CURLOPT_RETURNTRANSFER, false); // also tried with TRUE

$status_code = curl_getinfo($ch, CURLINFO_HTTP_CODE);   //get status code
if (!curl_errno($ch)) {
  $info = curl_getinfo($ch);
  print_r($info);
} else {
	print curl_error($ch);
}
$result=curl_exec ($ch);
print($result);

curl_close ($ch);

symp_gist_jquery_js

$.ajax({
	type: 'GET',
	url: 'https:....', // url used is QA endpoint supplied (excluded here for security reasons)
	headers: {
		"Authorization": "Basic c3ltcGxlY3RpY1BTWUNISUFUUlk6YnJpZ2h0Ymx1ZXN0YWdl", //encoded username:password
	},
				
	success: function(data) {
		/* handle data here */
		console.log(data);
	},
	error: function(xhr, status) {
		/* handle error here */
		console.log(status);
	}
});