<iframe width="420" height="315" src="https://www.youtube.com/embed/tgbNymZ7vqY"> </iframe>
// Add this to your URL ?autoplay=1&mute=1 // example https://www.youtube.com/embed/9QTojZVR_Ec?autoplay=1&mute=1
<iframe width="560" height="315" src="https://www.youtube.com/embed/videoseries?list=PLQGSXoAiT2W4W8D3397nl4OB_GxfOmJk9" allowfullscreen></iframe>