Excluding search data while searching data in elastic search

We need to construct a json query string such that it should return the results which don't contain the search term anywhere in the document.

Can you please help us using Query DSL?

Try to use the simple query string query: https://www.elastic.co/guide/en/elasticsearch/reference/current/query-dsl-simple-query-string-query.html#_simple_query_string_syntax

you are able to negates a search token.