Domain Search Bar

@jeff_m66, The source code does not expose the backend functionality of the search form. However it does expose front-end things like CSS and HTML. You can see explore this by using a developer tool in your browser. For instance in Chrome try right-clicking on the search by and selecting “Inspect element”.

This plugin might be what you are looking for: https://codecanyon.net/item/wp-domain-checker/9959666?ref=gnge