How can I connect the Docusign API using Google Apps Script?

Question

Im trying to connect to the Docusign API using Google Apps Script, but I dont know how to do it. I got my Integration Key and also created a app password because I read in documentation that I needed it. I would like to know how can I get the access token and how to send envelopes using this API.

I tried with this but it doesnt work

This to get the token:

function obtencionToken() {

  var payload = {
    "grant_type": "password",
    "client_id": PropertiesService.getScriptProperties().getProperty('client_id'),
    "username": PropertiesService.getScriptProperties().getProperty('username'), ////The name of the app password I generated
    "password": PropertiesService.getScriptProperties().getProperty('password'), //The password of the app password I generated
    "scope": "api"
  }

  var data = generarQuery(payload)
  var params = {
    "method": 'post',
    "headers":
    {
      "content-type": "application/x-www-form-urlencoded",
    },
    "payload": JSON.stringify(data),
    "muteHttpExceptions": true
  }

  var response = UrlFetchApp.fetch('https://demo.docusign.net/restapi/v2/oauth2/token', params);
  console.log(params);
  console.log(response);

  console.info(response.getResponseCode())
  console.info(response.getContentText())

  var access_token_response = JSON.parse(response).access_token;

  console.log("access_token_response: " + access_token_response)

  /* save token in Propertyservice */
  PropertiesService.getScriptProperties().setProperty('token', access_token_response);

  return access_token_response;
}

The error of first function is: Error función 1

This to sent an envelope

function generarQuery(){

var payload = {
      //"documents": docs,
      "emailSubject": "Request a signature via email example",
      "templateId": "<TemplateID>",
      "recipients": {
        "signers": [
          {
            "email": full_name,
            "name": email_address,
            "recipientId": "1",
            "routingOrder": "1",
            "pageNumbers": "1",

            "tabs": {
              "signHereTabs": [

                {
                  "anchorString": "Firma Solicitante",
                  "anchorXOffset": "6.5",
                  "anchorYOffset": "-0.2",
                  "anchorIgnoreIfNotPresent": "false",
                  "anchorUnits": "cms",
                }
              ],
            },
          }
        ],

      },

      "status": "sent"
    }

  var options2 = {
    "method": "post",
    "headers":
    {
      "Authorization": "Bearer"+ token2,
      "content-type": "application/json"
    },

    "payload": JSON.stringify(payload),
    "muteHttpExceptions": true
  };

  var token2 = UrlFetchApp.fetch('https://demo.docusign.net/restapi/v2/accounts/<AccountId>/envelopes', options2);
  var id_sobre = (JSON.parse(token2).envelopeId);

  console.log(payload);
  console.log(options2);
  console.log(id_sobre);

  console.info(token2.getResponseCode())
  console.info(token2.getContentText())

  Logger.log(token2)
  Logger.log("ID: " + id_sobre)
  return id_sobre;
}

The error of second function is: Error función 2

Answer 1

There should be a space after "Bearer", so this is fixed code:

  var options2 = {
    "method": "post",
    "headers":
    {
      "Authorization": "Bearer "+ token2,
      "content-type": "application/json"
    },