Determine the county for an address

<script>
  var api_key = 'YOUR-API-KEY';
  var address = '215 West 10th Street, Pueblo, CO 81003, USA';  // an address in Colorado

  var api_url = 'https://api.opencagedata.com/geocode/v1/json'

  var request_url = api_url
    + '?'
    + 'key=' + api_key
    + '&q=' + encodeURIComponent(address)
    + '&pretty=1';

  // see full list of required and optional parameters:
  // https://opencagedata.com/api#forward

  var request = new XMLHttpRequest();
  request.open('GET', request_url, true);

  request.onload = function() {
      // see full list of possible response codes:
      // https://opencagedata.com/api#codes
      var data = JSON.parse(request.responseText);
      if (request.status === 200){  // Success!
          var county = 'no county returned';
          if (data.results[0].components.county != null){
              county = data.results[0].components.county;
          }
          var fips_code = 'no FIPS code returned';                  
          if (data.results[0].annotations.FIPS.county != null){
              fips_code = data.results[0].annotations.FIPS.county;
          }
          console.log('county: ' + county);       // prints "Pueblo County"
          console.log('FIPS code: ' + fips_code); // prints "08101"
      } else {
          console.log("unable to geocode! Response code: " + request.status);
          console.log('error msg: ' + data.status.message);
      }
  };

  request.onerror = function() {
      // There was a connection error of some sort
      console.log("unable to connect to server");
  };
  request.send();  // make the request
</script>