Hello. There are two broad methods. One is to process the results of a normal web search using a programming language such as Python and pass the results to LLM yourself. The other is a method called Function Calling, in which you instruct LLM to execute a search tool and return the results. (There are various names for this method.)
In the case of the former, there are various useful libraries, so you should try searching for them. If you can use the latter, it is usually built into the LLM execution environment, so it is often found somewhere in the documentation.
Pass the results of a normal web search to LLM
https://pypi.org/project/duckduckgo-search/