Can not insert multiple videos into a playlist - YouTube API v3

Question

I am trying to add multiple videos to a playlist, but only one video is added to the playlist. I can successful create a playlist and insert a video to the playlist, but can

Answer 1

In addition to Rohan's answer, the function call at the bottom should be:

function myLoop(video_id) {
    addToPlaylist(video_id);
    setTimeout(function() {
        counter++;
        if(counter < links.length)
            myLoop(links[counter]);
    }, 3000);
}

It lacked "video_id" as a parameter.

It worked good for me.

The whole, working code is:

// Global array holds links and a global counter variable
var links = [
  "wtLJPvx7-ys",
  "K3meJyiYWFw",
  "3TtVsy98ces"
]
var counter = 0;

function addVideosToPlaylist() {
    myLoop(links[0]);
}

function myLoop(video_id) {
    addToPlaylist(video_id);
    setTimeout(function() {
        counter++;
        if(counter < links.length)
            myLoop(links[counter]);
    }, 3000);
}