JAVASCRIPT

json stringify double quotes

var data = {
	name: "himanshu",
    github: "himanshurajora"
}
var strData = JSON.stringify(data)

// json stringify by default gives us double quotes
// you can setup the same format as json itself

var strData = JSON.stringify(data, null, 4)

json stringify without quotes

Use JSON5.stringify
JSON5 is a superset of JSON that allows ES5 syntax, including unquoted property keys. The JSON5 reference implementation (json5 npm package) provides a JSON5 object that has the same methods with the same args and semantics as the built-in JSON object.

It is highly likely that the service you are using is using this library.