How to Create Google Custom Search Engine https://youtu.be/3bJfuawToUE details how you can create your very own Google Custom Search Engine for your web site
First make sure that the website you want to create a custom search for is verified in Google Webmaster Tools
Then visit this URL
And simply create your very own Google Custom Search Engine to use on your own website. You can use the free version or if you want to get Google Custom Search Engine for your business, then you can also create one for your business.
You can also watch this video from Google Webmasters on YouTube “Introduction to Google Custom Search”
To share this video tutorial by RankYa use this
Visit the help centre to learn more about How to create your very own Google Custom Search Engine for your website