.htaccess

RewriteEngine on
ErrorDocument 404 /My-Blog/Admin/404.php

ErrorDocument 403 /My-Blog/Admin/404.php

#remove php file extension-e.g. https://example.com/file.php will become https://example.com/file
RewriteEngine on 
RewriteCond %{REQUEST_FILENAME} !-d
RewriteCond %{REQUEST_FILENAME}\.php -f
RewriteRule ^(.*)$ $1.php [NC,L]

#remove html file extension-e.g. https://example.com/file.html will become https://example.com/file
RewriteEngine on 
RewriteCond %{REQUEST_FILENAME} !-d
RewriteCond %{REQUEST_FILENAME}\.html -f
RewriteRule ^(.*)$ $1.html [NC,L]

Options -Indexes