Redirect to 404 error page will allow you to set the message that visitors to your site receive when they request a page that doesn’t exist on the server.
Setting this up redirection of 404 error page is quite easy in .htaccess file.
Now, edit/create .htaccess file and add following line.
ErrorDocument 404 /404.html
After you’ve made your edit, click on Save Changes.
Now, if you try to pull up a page that won’t exist on the server such as /Iamnotexists.html you should see the custom 404 error message that we’ve configured.