WordPress ajouter une double authentification sur le back office grâce à htaccess

<FilesMatch "^(?!401\.php$).+">
AuthName "site protegee"
AuthType Basic
AuthUserFile "/path/to/.htpasswd"
Require valid-user
</FilesMatch>

ErrorDocument 401 /401.php

# BEGIN WordPress
#<IfModule mod_rewrite.c>
#RewriteEngine On
#RewriteBase /
#RewriteRule ^index\.php$ - [L]
#RewriteCond %{REQUEST_FILENAME} !-f
#RewriteCond %{REQUEST_FILENAME} !-d
#RewriteRule . /index.php [L]
#</IfModule>

# END WordPress

Comprendre la Directive FileMatch