Understanding the Issue

The error message "youtube.com refused to connect" can be frustrating, especially when we are confident that the code seems correct and the URL of youtube is also correctly copied.

But still, you can refer to the below code :

Expected URL to be copied = https://youtu.be/XbGs_qK2PQA
Corrected URL relevant to iframe = https://youtube.com/embed/XbGs_qK2PQA

<iframe src="https://youtube.com/embed/XbGs_qK2PQA" frameborder="0" allowfullscreen></iframe>

Also don't forget to use '/embed' keyword in the URL.