Enable 'SSLProxyEngine On' for single domain on server in apache vhosts

Hi, I am looking for docs on how to enable SSLProxyEngine for a single domain in Apache. I read I have to add some lines to vhosts file of specific domain. I found some docs that point me to the following location > /etc/apache2/conf.d/userdata/ssl/2_4/cpanelusername The weird thing is that not ALL my cpanel usernames are listed there. I even see some old depreciated usernames. Should I look in other location ? In short, where do I find the vhost file of this specific domain where I need to add the code to enable SSLProxyEngine for that domain ? Thanks