How to make a redirect by a label in a link?

Question

URL Handling

there is a link site.ru/?1111
how to make it so that when you go with such a referrer (1111), site1.ru opens,
if without a referrer, then site2.ru

Answer 1

RewriteCond %{HTTP_HOST} ^site\.ru$
RewriteCond %{QUERY_STRING} (^|&)1111($|&)
RewriteRule ^$ https://site1.ru/? [L,R=301]


RewriteCond %{QUERY_STRING} !(.+)
RewriteCond %{HTTP_HOST} ^site\.ru$
RewriteRule ^$ https://site2.ru/? [L,R=301]

something like this