Google App Script - PayPal API - Get Access Token

Question

I have this function that should give me the access token in cURL

curl -v https://api.sandbox.paypal.com/v1/oauth2/token \
    -H "Accept: application/json" \
    -H "Accept-Language: en_US" \
    -u "client_id:secret" \
    -d "grant_type=client_credentials"

source:https://developer.paypal.com/docs/api/overview/#get-an-access-token

but when i try to run the function (that is supposed to be the same) in google app script the error is always: "invalid token". What am i doing wrong?

 function lol(){
   var request = UrlFetchApp.fetch("https://api.sandbox.paypal.com/v1/oauth2/token", {
     "Accept": "application/json",
     "Accept-Language": "en_US",
     "CLIENT_ID":"SECRET",
     "grant_type":"application/x-www-form-urlencoded"
   })
   Logger.log(request.getContentText());
 }

CLIENT_ID & SECRET are personal and copied from my PayPal account.

Answer 1

How about this modification?

Modification points :

• At UrlFetchApp, as Sandy Good said, you are required to explicitly designate the method. In your case, it's "POST".
• At UrlFetchApp, the default Content-Type is application/x-www-form-urlencoded.
• The option -u for curl command is the basic authorization.
• The option -H for curl command is the header.
• At the curl sample of PayPal, grant_type is client_credentials.

The script which reflected above points is as follows.

Modified script :

function myFunction(){
  var client_id = "client_id"; // Please input your client_id
  var secret = "secret"; // Please input your client secret

  var options = {
    method: "post",
    headers : {
      "Authorization" : " Basic " + Utilities.base64Encode(client_id + ":" + secret),
      "Accept": "application/json",
      "Accept-Language": "en_US"
    },
    payload: {"grant_type": "client_credentials"}
  };
  var request = UrlFetchApp.fetch("https://api.sandbox.paypal.com/v1/oauth2/token", options);
  Logger.log(request.getContentText())
}

If this was not useful for you, I'm sorry.