Proper way to perform a helix API call Using JavaScript

API
7

The items you linked to helped a lot. But I am still having some trouble getting everything working properly.
I have been able to perform the call correctly, but in ordfer to streamline my code I decided to functionize the call.
My major is that my function “APICall” just refuses to ‘return’ data (either the JSON object or a simple string. Neither is returning to parent call.). I verified this by having the 'document.write(“Response Received”) line in the parent routine ‘CheckStreamerOnline’.

I have been testing my code on : https://js.do/ for quick and easy testing, so all of the ‘document.write’ stuff is to get output there. (You can copy-paste this write into that page to get a live result)

Here is my code:

<script>
const oAuthorizationURL = 'https://id.twitch.tv/oauth2/authorize?' ;
const ImplicitAuthURL = 'https://api.twitch.tv/helix/users?' ;
const TokenValidationURL = 'https://api.twitch.tv/helix/' 
//'https://id.twitch.tv/oauth2/validate'
const TokenURL = 'https://id.twitch.tv/oauth2/token?' ;
const StreamsURL = 'https://api.twitch.tv/helix/streams?'
const AppRedirectURL = 'http://localhost'
const AppClientID = 'y4344ir7sj3tem9cqnzkv288grm4e9'
var ApiToken = 'REMOVED'
 
 
async function APICall(URL, HeadersObject) {
  // Perform API Call and return a JSON object
  document.write("<br> Performing API Call to URL: " + URL)
  fetch( URL ,   { headers: HeadersObject   } )
  .then(resp => resp.json())
  .then(resp => {
  	if (resp.error) {
			document.write("<br> URL: " + URL)
        document.write("<br>")
        document.write("<br>API Response:")
        document.write("<br>")
			document.write("Error: " + resp.error)
        document.write("<br>")
        document.write("Status: " + resp.status)
        document.write("<br>")
        document.write("Message: " + resp.message)
        document.write("<br>")
        return "ERROR"
  	}else {
    	document.write("<br>API Returned without error <br>")
    	document.write("<br><br> Literal Reponse: <br>")
  			document.write(JSON.stringify(resp) + "<br><br>")
	      	return resp.json()
  	}	
  })
  .catch(resp,err => {
document.write('🤬 API Access Error: ', err);
try {
	document.write("<br><br> Literal Reponse: <br>")
  		document.write(JSON.stringify(resp) + "<br><br>")
    }
    finally{ return ERROR };
  });
  return "ERROR"
};  
 
async function CheckStreamerOnline(ChannelURL) {
  var bolONLINE = false;
  if (ChannelURL ===  'NoValueSet' || ChannelURL ===  '' || ChannelURL ==  null ) {  
  // No Value -> Ignore
  bolOnline = false; 
  } else { 
  	//Perform API check to determine if the specific channel is online
var myHeaders = new Headers(); // Currently empty
myHeaders.append("Client-ID", AppClientID)
myHeaders.append("Authorization", "Bearer " + ApiToken)

var Resp = await APICall(StreamsURL + 'user_login=' + ChannelURL, myHeaders);
document.write("<br>Response Received<br>")
if (Resp.data[0]){
	bolONLINE =  TRUE
    }else {
    bolONLINE = FALSE         
    };
    
};   // end of large if statement    
return bolONLINE
  };



async function main() {
  document.write("<br>" +"=========================");
  var R = await CheckStreamerOnline('warframe');
  document.write("<br>CheckStreamerOnline Response: <br>" + R);
};

main();
</script>