How to redirect from a subdomain to a link (.htaccess)?

Question

htaccess

Good time of the day
Such a question:
You need to do a redirect using .htaccess
, for example, there is a site example.com (on the hosting there is only 1 folder with the name of the site, there are no others)
The user makes a request help.example.com, but in fact that he would get to example.com/page.php?tag=help
and it is not known in advance which subdomain the user will knock on.
Thanks in advance!

Answer 1

RewriteCond %{HTTP_HOST} ^help\.example\.com$
RewriteRule ^.*$ http://example.com/page.php\?tag=help [L,R=301]