If your website is using long URL like example.com/files/folder/sitemap.html, you can change it into "example.com/sitemap" in .htaccess
Modify this line according to your needs and then add this code to your .htaccess file.
RewriteEngine on
RewriteRule ^sitemap/$ /files/folder/sitemap.html [L]
How to redirect a page to another page or website using .htaccess?
If a page on your website no longer exist and you want to redirect it to your new page or website...