Edit user signature, but can't use Oauth - google-apps-script

Question

I'm tryng to edit the users signature via GAS.
I have found lots of examples and tutorials, and one of the Waqar Ahmad's answers looks very good - Email Settings APIs Authentication.
However, it doesn't work for me.
I don't really understand OAuth autorization, but couldn't find a tutorial for it.
With what should I replace anonymous?
oAuthConfig.setConsumerKey("anonymous");
oAuthConfig.setConsumerSecret("anonymous");
I go to https://console.developers.google.com/ create a project and use clientID for key and client secret for secret, is it right?
Adding more information:
This is the Waqar's code I'm using:
/*-----------------------------------------------------------------------------
This function will update the HTML signature of a user.
Input will be jason data
To disable signature, pass an empty string as signature value
sample parameter
ob = {user='hps', signature='<b>Regards</b><br>Waqar'}
To disable signature
ob = {user='hps', signature=''}
-----------------------------------------------------------------*/
function updateSignature(ob) {
//ob = {};
//ob.user = "hps";
//ob.signature = "<b>Regards</b><br>Waqar";
ob = {};
ob.user = "test#xxxx.it";
ob.signature = "<b>Regards</b><br>Waqar";
var base = 'https://apps-apis.google.com/a/feeds/emailsettings/2.0/';
var xmlRaw = '<?xml version="1.0" encoding="utf-8"?>'+
'<atom:entry xmlns:atom="http://www.w3.org/2005/Atom" xmlns:apps="http://schemas.google.com/apps/2006">'+
'<apps:property name="signature" value="'+htmlEncode(ob.signature)+'" />'+
'</atom:entry>';
var fetchArgs = googleOAuth_('emailSetting',base);
fetchArgs.method = 'PUT';
fetchArgs.payload = xmlRaw;
fetchArgs.contentType = 'application/atom+xml';
var domain = UserManager.getDomain();
var url = base+domain+'/'+ob.user+'/signature';
var urlFetch = UrlFetchApp.fetch(url, fetchArgs);
var status = urlFetch.getResponseCode();
return status;
}
//--------------------------------------------------------------------------
//This function will retreive Signature settings as json.
/*Sample returned object
{user=hps, signature=<b>Regards</b><br>Waqar}
*/
//-----------------------------------------------------------------
function retrieveSignature(user) {
var user = 'hps';
var base = 'https://apps-apis.google.com/a/feeds/emailsettings/2.0/';
var fetchArgs = googleOAuth_('emailSetting',base);
fetchArgs.method = 'GET';
var domain = UserManager.getDomain();
var url = base+domain+'/'+user+'/signature?alt=json';
var urlFetch = UrlFetchApp.fetch(url, fetchArgs);
var jsonString = urlFetch.getContentText();
var jsonArray = Utilities.jsonParse(jsonString).entry.apps$property;
var ob = {};
ob.user = user;
for(var i in jsonArray){
ob[jsonArray[i].name] = jsonArray[i].value;
}
return ob;
}
//Google oAuthConfig..
function googleOAuth_(name,scope) {
var oAuthConfig = UrlFetchApp.addOAuthService(name);
oAuthConfig.getAccessTokenUrl()
oAuthConfig.setRequestTokenUrl("https://www.google.com/accounts/OAuthGetRequestToken?scope="+scope);
oAuthConfig.setAuthorizationUrl("https://www.google.com/accounts/OAuthAuthorizeToken");
oAuthConfig.setAccessTokenUrl("https://www.google.com/accounts/OAuthGetAccessToken");
oAuthConfig.setConsumerKey("xxxxxxxxxxxx.apps.googleusercontent.com");
oAuthConfig.setConsumerSecret("xxxxxxxx-xxxxxx-xxxxx");
return {oAuthServiceName:name, oAuthUseToken:"always"};
}
//This function will escape '<' and '>' characters from a HTML string
function htmlEncode(str){
str = str.replace(/</g,'<');
return str.replace(/>/g,'>')
}
to get the oAuthConfig.setConsumerKey and oAuthConfig.setConsumerSecret I have created a new project in the google developer console, modified to on the Admin SDK API status, created a "Client ID for native application" and used the CLIENT ID in setConsuperKey, and CLIENT SECRET in setConsumerSecret.
Executing the script updateSignature the test#xxxx.it's signature should be changed,
I can see the box "autorization required" clik ok, and appear the request access box,
i click on "grant access" but nothing happes, and no error are shown.
Executing the same function in debug mode, i have the same boxes and a red box with "Errore OAuth" at the end.
I'm doing something wrong... please help me to find the mistake!!
Thanks again.
Marco

Answer 1

Finally i found the clue!!
Thank's to mike's quastions and answers
who let me discover This example
I Finally understand!!
in consumerkey you have to set your domain (p.e. "mydomain.it",
in consumerSecret you have to set the "Secret data of the customer to OAuth:" from admin google console->secority->advanced settings->Manage data OAuth key and secret for this domain.
I was confusing by the secret key in the google developer console, may be this answer can help