API call to directory.members.insert failed with error: Resource Not Found: groupKey

Question

I'm working on a script for Google Sheets that adds members to a specific Google Group using emails found in the data. The Google Group seems to be found and the Google Group's email/groupKey is returned correctly. The currentUser in the session (me) is a member of the group (owner). I have enabled the Admin Directory API. In one test, I even called group.getUsers() and all the members of the group are correctly returned. All the values in logging are as expected.

Why is the call to insert still failing? What is the member not added to the google group?

I've included code and log.

Code

function addMembersFromSheet() {
  var sheet = SpreadsheetApp.getActiveSpreadsheet().getSheetByName("MySheet");
  var emails = sheet.getRange(2,3,sheet.getLastRow()-1,1).getValues();
  Logger.log(emails);
  
  var currentUser = Session.getActiveUser();
  Logger.log(currentUser);
 
  var group = GroupsApp.getGroupByEmail("<mygroup>@googlegroups.com");
    
  if (group.hasUser(currentUser)) {
    Logger.log("You are a member of this group. group is: ");
    Logger.log(group.getEmail()); //correctly finds the group
  
  }
  else {
    Logger.log("You are not a member of this group.");
  }

  for(i = 0; i < emails.length; i++) {
    try {
      addMember(emails[i][0], group);
    }
    catch(e) {
      console.error(e);
      Logger.log(e);
      continue;
    }   
  }
}

function addMember(email, group) {
  
  var hasMember = group.hasUser(email);
  Logger.log(hasMember);
  Utilities.sleep(1000);
  
  if(!hasMember) {
    var newMember = {email: email, 
                     role: "MEMBER",
                     delivery_settings: "NONE"};
    Logger.log(newMember);
    Logger.log(group.getEmail())
    AdminDirectory.Members.insert(newMember, group.getEmail());
  }
}

Logging output(with some changes to private details):

Jul 26, 2020, 3:22:09 PM    Info    [[<testmember>@gmail.com]]
Jul 26, 2020, 3:22:09 PM    Info    <currentUser>@gmail.com
Jul 26, 2020, 3:22:10 PM    Info    You are a member of this group. group is: 
Jul 26, 2020, 3:22:10 PM    Info    <mygroup>@googlegroups.com
Jul 26, 2020, 3:22:10 PM    Info    false
Jul 26, 2020, 3:22:11 PM    Info    {delivery_settings=NONE, role=MEMBER, email=<testmember>@gmail.com}
Jul 26, 2020, 3:22:11 PM    Info    <mygroup>@googlegroups.com
Jul 26, 2020, 3:22:11 PM    Error   { [GoogleJsonResponseException: API call to directory.members.insert failed with error: Resource Not Found: groupKey]
  details: 
   { code: 404,
     message: 'Resource Not Found: groupKey',
     errors: [ [Object] ] },
  name: 'GoogleJsonResponseException' }
Jul 26, 2020, 3:22:11 PM    Info    GoogleJsonResponseException: API call to directory.members.insert failed with error: Resource Not Found: groupKey

Answer 1

You are retrieving a group of a consumer account and try to perform on it methods of A GSuite Admin

• From your group name (ending with googlegroups.com) I can assume that you have a consumer account (free Gmail account)
• However, methods of the class AdminDirectory are only available to administrators of GSsuite accounts. The documentation specifies:

This API gives administrators of G Suite domains (including resellers) the ability to manage devices, groups, users, and other entities in their domains.

• So, with a consumer account unfortunately you are not allowed to use the AdminDirectory to insert users programmatically.
• You are allowed to use GroupsApp, but this service does not have methods for insertion of users.