First go to youtube and type video name that you want to put to your website
Second open the video and click to the share button
After you will click share button this screen will appear and you should click the button as it is shown in the screenshot
As soon as you click the button the new screen will appear and at the right side of the screen you will see code you should copy it
After you copy it just paste it into your code and you will get results as it is shown below