How to set up ErrorDocument 404 in Apache?

Question

Apache HTTP Server

I wrote in .htaccess:
ErrorDocument 404 /404.html
Created a 404.html page.
The question is how to give a 404 error just when visiting /404.html without using php and other things. Simply means of apache. That is, not when the page is not found and apache displays this page and issues a 404, but when you just go to /404.html