SOURCE

canvas = document.getElementById('canvas');
editor = new Editor(canvas);
musicNode = editor.audio("https://sf1-dycdn-tos.pstatp.com/obj/eden-cn/4201eh7nuhpephbozupq/creative-video-editor/test1.mp4", {
    type: Editor.AUDIOEFFECT.FADE,
    useEffect: true,
    volume: 1,
});
musicNode.timelineStart(0);
musicNode.timelineStop(5);
musicNode.fade = {
          inTime: 0,
          outTime: 0,
        };

        musicNode1 = editor.audio("https://sf1-dycdn-tos.pstatp.com/obj/eden-cn/4201eh7nuhpephbozupq/creative-video-editor/test1.mp4", {
    type: Editor.AUDIOEFFECT.FADE,
    useEffect: true,
    volume: 1,
});
musicNode1.timelineStart(5);
musicNode1.timelineStop(10);
musicNode1.fade = {
          inTime: 0,
          outTime: 0,
        };




musicNode.connect(editor.output);
musicNode1.connect(editor.output);

let wrapper = document.getElementById('wrapper');
let interactiveBox = editor.initInteractiveBox(wrapper);
InitVisualisations(editor, 'timeline-canvas', 'current')
let graphCanvas = document.getElementById('graph');
Editor.utils.visualiseVideoContextGraph(editor, graphCanvas);

window.editor = editor;

// play button
playButton.onclick = editor.play.bind(editor);
pauseButton.onclick = editor.pause.bind(editor);
replayButton.onclick = function () {
    editor.currentTime = 0;
    editor.play();
}

<div class="wrapper" id="wrapper">
	<canvas width="640" height="360" id="canvas"></canvas>
</div>
<p>
	<button id="playButton">play</button>
    <button id="pauseButton">pause</button>
    <button id="replayButton">replay</button>
    <button id="speed">speed</button>
</p>
<p id="current">

</p>
<p>
    <canvas id="timeline-canvas" width="640" height="20"></canvas>
</p>
<p>
    <canvas id="graph" width="640" height="320"></canvas>
</p>

html {
  font-family: monospace;
  color: #333;
}
.wrapper {
        position: relative;
        width: 640px;
        height: 360px;
        overflow: hidden;
    }
#canvas {
  width: 640px;
  height: 360px;
}
#current {
  font-size: 12px;
}
input {
  width: 50px;
}
button {
  line-height: 1.499;
  position: relative;
  display: inline-block;
  font-weight: 400;
  white-space: nowrap;
  text-align: center;
  background-image: none;
  border: 1px solid transparent;
  cursor: pointer;
  user-select: none;
  height: 32px;
  padding: 0 15px;
  font-size: 14px;
  border-radius: 4px;
  color: rgba(0,0,0,0.65);
  background-color: #fff;
  border-color: #d9d9d9;
  outline: 0;
  transition: all .3s cubic-bezier(.645, .045, .355, 1);
}

button:hover {
  color: #40a9ff;
  background-color: #fff;
  border-color: #40a9ff;
}

.button:active {
  color: #096dd9;
  background-color: #fff;
  border-color: #096dd9;
}
input {
  -webkit-appearance: none;
  background-color: #fff;
  background-image: none;
  border-radius: 4px;
  border: 1px solid #dcdfe6;
  box-sizing: border-box;
  color: #606266;
  display: inline-block;
  font-size: inherit;
  height: 32px;
  line-height: 32px;
  outline: none;
  padding: 0 8px;
  transition: border-color 0.2s cubic-bezier(0.645, 0.045, 0.355, 1);
  width: 50px;
}