Récupérer valeur collection json node newman

Hello everyone,

I need your help please.
I would like to retrieve a value from the json. a variable.
how can i get it back please? I tried the command in the .js

const newman = require(‘newman’),
fs = require(‘fs’);
const request= Math.random().toString(36).substring(7) + ‘-request.txt’;

newman.run({
collection: require(‘./G-test1.postman_collection.json’),
iterationData: ‘./data.csv’,
environment : require(‘./Recette Externe Copy.postman_environment.json’),
reporters: ‘cli’,
iterationCount : 1

}).on(‘request’, function (error, args) {
if (error) {
console.error(error);
}
else {

    fs.appendFile(request,     args.item.request.auth.basic[1].key  , function (error) {

        if (error) { 
            console.error(error); 

        }
    });        
}	

});

my json

},
		"request": {
			"auth": {
				"type": "basic",
				"basic": [
					{	"key": "password",
						"value": "{{MDP}}",
						"type": "string"
					},
					{	"key": "username",
						"value": "{{NOM_OP}}",
						"type": "string"
					}
				]
			},
			"method": "POST",
			"header": [
				{
					"key": "OP",
					"value": "{{NOM_OP}}",
					"type": "text"
				}
			],
			"body": {
				"mode": "raw",
				"raw": "{    \r\n    \"

Thankyou