How to configure the search button in Dreamweaver?

The search form in Bootstrap doesn't DO anything out of the box. It needs to be connected to an actual search engine script.

First you need a searchable website like WordPress with content stored in a database (PHP & MySQL) or some other data source (JSON, XML or MSSQL).   Static HTML sites are not searchable.

In the absence of a searchable database,  you'll need to rely on 3rd party search engines like Google or FreeFind (some fees may apply).

Google Search API

https://developers.google.com/custom-search/v1/overview

Freefind Search Engine (free and paid versions available).

https://www.freefind.com/

Once you have your search engine set-up and your site is fully indexed, come back and we can provide more details on how to make it work with the Bootstrap search form.

This is a very very broad question that falls outside the scope of this forum. We are here to help with specific problems, not to supply a whole tutorial.

Having said that that, I did a simple Bing search and found this little gem:

https://dev.to/am20dipi/how-to-build-a-simple-search-bar-in-javascript-4onf

I hope it helps.