@indikauih said:
Is there a way to search by Genres?
What I want is
1 - not filter by Genre
2 - but get a result set (response) based on a Genre search.

In the translation into my language, your question became meaningless.
I can't understand the difference between searches that you reported:
1 - filter by Genre
2 - response based on a Genre search

Using a Discovery API Request you can determine that you want to receive only Movies that have the genre, for example, War.
I believe that this research is what you call with Filter by Genre, your first option.
If I'm sure, then, what do you want to receive in the answer to your second option?

EDIT
Perhaps what you want to know is the Genres used in TMDb, with their respective IDs.
In this case, receive the list by making this API Request:
https://developers.themoviedb.org/3/genres/get-movie-list

He wants to search movies by genre.

Currently this is not possible (at least according to the documentation), but it would also not making any sense.

What you can do is to get similar movies => /movie/{movie_id}/similar

I know this is an old thread, but in case it helps someone in the future:

The documentation doesn't make this clear (at least to me), but you can search by genre using the Discover Movie search (example here. You add a genre by itself and then your results will be all movies that include that genre. There are lots of other filters as well for excluding or included other things.