How to make a Json parse without changes in Google Apps Script - json

Question

I make a request to Go to Webinar API in Apps Script and the response is something like this:
{"joinUrl":"https://example.com","asset":true,"registrantKey":3669516009270899211,"status":"APPROVED"}
When I make a JSON.parse i get something like this:
{joinUrl=https://example.com, asset=true, registrantKey=3.6695160092708992E18, status=APPROVED}
The RegistrantKey changes, I dont know why.
Thats my code:
try{
var resp = UrlFetchApp.fetch(url,options)
var json=JSON.parse(resp);
return json
}catch(err){
Logger.log(err);
return err;
}

Answer 1

How about this answer? Please think of this as just one of several possible answers.
Issue and workaround:
I think that the reason of your issue is that 3669516009270899211 of "registrantKey":3669516009270899211 is used as the number. In Javascript, the maximum integer value is 9007199254740991. Ref So when 3669516009270899211 is converted to the number, it becomes 3.6695160092708992E18 and when this is converted to the string, it becomes 3669516009270899000.
So in this case, as one of several workaround, how about enclosing 3669516009270899211 by the double quotes like "registrantKey":"3669516009270899211"? By this, "3669516009270899211" is used ad the string, and you can retrieve the value of 3669516009270899211.
Modified script:
When your script is modified, how about the following modification?
From:
var resp = UrlFetchApp.fetch(url,options)
var json=JSON.parse(resp);
return json
To:
var resp = UrlFetchApp.fetch(url,options);
resp = resp.getContentText().replace(/registrantKey":(\d.+),/, "registrantKey\":\"$1\","); // Added
var json=JSON.parse(resp);
return json
Note:
As the test script, you can also use the following script.
var str = '{"joinUrl":"https://example.com","asset":true,"registrantKey":3669516009270899211,"status":"APPROVED"}';
str = str.replace(/registrantKey":(\d.+),/, "registrantKey\":\"$1\",");
var obj = JSON.parse(str);
Logger.log(obj)
Reference:
Number.MAX_SAFE_INTEGER
If I misunderstood your question and this was not the direction you want, I apologize.