how to get the thumbnail from a youtube video code example

Example: youtube video image

<!-- thumbnail -->
https://img.youtube.com/vi/<insert-youtube-video-id-here>/mqdefault.jpg

<!-- Others -->
https://img.youtube.com/vi/<insert-youtube-video-id-here>/default.jpg
https://img.youtube.com/vi/<insert-youtube-video-id-here>/0.jpg
https://img.youtube.com/vi/<insert-youtube-video-id-here>/1.jpg
https://img.youtube.com/vi/<insert-youtube-video-id-here>/2.jpg
https://img.youtube.com/vi/<insert-youtube-video-id-here>/3.jpg