How to set up a 404 error in Datalife?

Question

PHP

Here is an example of a server response when opening a non-existent category on the site:
www.bertal.ru/index.php?a2566748/multmult.com/web/...
First comes HTTP/1.1 301 Moved Permanently
then HTTP/1.1 302 Found
then HTTP/ 1.1 200 OK
I can't figure out which file to set up so that initially when opening a non-existent category it gives 404 error?
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The same problem if you open a deleted article: multmult.com/341-malysh-barboskiny.html
301-302-200
And I need to immediately give 404 .. I do not understand how! I have already deleted all 301 headers from engine and show.full .. but it still gives