Setting url suffix

This is a kludge of course (Codeigniter 4 should support this natively in my opinion) but you can do something like this.  The regular expression addition strips off any .html extension before continuing on processing the route.  This allows requests to work with or without ".html" as the file extension present in the original request. 

./system/Router/Router.php

Line 173:

        // Decode URL-encoded string
        $uri = urldecode($uri);
       
        // kludge to work around .html extension on existing links
        $uri = preg_replace('/(.*)\.html(\?.*)?$/','\1\2',$uri);