ACS Friend system won't work?

Hello. I am showing a list of all the users in my app. When the logged in user presses the user, it should Add him or her as a friend, but instead it is giving me this error:

message = "'undefined' is not an object (evaluating 'Cloud.Friends.add')";

And yes, I have included the require Cloud code, because I am using it for alot of other things in same file. Currently I am using this code to add friends:

table.addEventListener('click', function(e){
    Cloud.Friends.add({
        user_ids: checked.join(e.row.id)
    }, function (e) {
        if (e.success) {
            alert('Friend(s) added');
        } else {
            alert('Error:\\n' +
                ((e.error && e.message) || JSON.stringify(e)));
        }
    });   
  });

I have also tried to manually add an ID to the user_ids, like this:

user_ids: checked.join("5028de86002044626f0c8393")