<IfModule mod_rewrite.c>
    RewriteEngine On

    # Remove "index.php" from the URL admin url
    RewriteCond %{THE_REQUEST} \s/index\.php [NC]
    RewriteRule ^index\.php$ /admin [R=301,L]

    # Redirect "/admin" to serve "index.php" internally
    RewriteCond %{REQUEST_FILENAME} !-f
    RewriteCond %{REQUEST_FILENAME} !-d
    RewriteRule ^$ index.php [L]
</IfModule>