Copy and paste the code in .htaccess file.
ErrorDocument 401 /path-to-your-site/index.php?error=404 ErrorDocument 403 /path-to-your-site/index.php?error=404 <IfModule mod_rewrite.c> RewriteEngine on RewriteCond %{REQUEST_URI} ^(.*)?wp-login\.php(.*)$ [OR] RewriteCond %{REQUEST_URI} ^(.*)?wp-admin$ RewriteCond %{REMOTE_ADDR} !^IP Address One$ RewriteCond %{REMOTE_ADDR} !^IP Address Two$ RewriteCond %{REMOTE_ADDR} !^IP Address Three$ RewriteRule ^(.*)$ - [R=403,L] </IfModule>