setting sub domain variable in apache

I have an issue trying to get the subdomain as a variable and use it somewhere in another part

what I'm trying to do is a proxy configuration that allow me to connect between

aaa.example-example.com will show me example.com/aaa

and

bbb.example-example.com will show me example.com/bbb

my code :

 <IfModule mod_ssl.c>
<VirtualHost *:443>
    ServerName wildcard.example.com
    ServerAlias *.example.com
    ServerAdmin webmaster@localhost
    ProxyRequests Off
    
    <Proxy *>
        Order deny,allow
        Allow from all
    </Proxy>
    
    ErrorLog ${APACHE_LOG_DIR}/error.log
    CustomLog ${APACHE_LOG_DIR}/access.log combined

# the pattern of my website look like example-example.com 
    SetEnvIf Host "^([^.]*).example-example.come$" SUBDOMAIN=$1 

    SSLProxyEngine on
    ProxyPass / https://example1.com/%{ENV:SUBDOMAIN}
    ProxyPassReverse / https://example1.com

    Include /etc/letsencrypt/options-ssl-apache.conf
    SSLCertificateFile /etc/letsencrypt/live/example.com-0001/fullchain.pem
    SSLCertificateKeyFile /etc/letsencrypt/live/example.com-0001/privkey.pem
</VirtualHost>
</IfModule>

so SetEnvIf is not working and always printing %{ENV:SUBDOMAIN} instead of the actual subdomain

I have the exact problem explained in

https://stackoverflow.com/questions/36199764/setting-the-subdomain-as-a-variable-in-apache-config-to-be-used-in-the-same-conf

but I already have the same solution and it didn't work

I'm using Apache/2.4.29 (Ubuntu) I'm happy with any solution to the variable in the ProxyPass part.

thanks