You Should Add [XYZ] to the httpd Config File
As you’re on Apache, you should add the following include to the website httpd config file:
When you disable PHP redirects and generate a separate redirect file, the plugin writes all redirects to a custom file. However, your server doesn’t know to use the custom file. The included command tells the server to use the custom file.
Your webhost or server administrator can provide instructions on how to edit the httpd config file for your website.