htaccess redirect with query string not working - .htaccess

Question

enter code hereI have a WordPress website.
I have URLs for affiliates that look like this:
https://example.com/folder/?ref=23432
https://example.com/folder/?ref=13442
etc.
I would like to redirect any URL that ends in ?ref= to another domain.
For example, https://example.com/folder/?ref= should redirect to https://example.org/product/
How can I do this? I appreciate your time.
I tried
Redirect 301 example.com/folder/?ref https://example.org/product/
Thank you #MrWhite. I tried the following with no success.
RewriteEngine On
RewriteCond %{QUERY_STRING} (^|&)ref=
RewriteRule ^example.com https://www.example.org/product/$0 [R=302,L]

Answer 1

RewriteRule ^example.com https://www.example.org/product/$0 [R=302,L]
The RewriteRule directive matches the URL-path only (less the slash prefix). So this should be matching against folder/ (as per your example), not the hostname.
And the $0 backreference in the substitution string is not required here. So this should simply be:
:
RewriteRule ^folder/$ https://www.example.org/product/ [R=302,L]
If you do need to check the requested hostname (ie. example.com) - if example.com and example.org point to the same server - then you need a separate condition (RewriteCond directive). For example, the complete rule would then become:
RewriteCond %{HTTP_HOST} ^(www\.)?example\.com [NC]
RewriteCond %{QUERY_STRING} (^|&)ref=
RewriteRule ^folder/$ https://www.example.org/product/ [R=302,L]
Note that the regex (^|&)ref= matches the ref= URL parameter anywhere in the query string, if there happened to be other URL parameters that preceded it.
Reference:
htaccess redirect URL with parameter when a special parameter exists
https://httpd.apache.org/docs/current/mod/mod_rewrite.html#rewriterule