Most of the company websites I handle are hosted on shared servers, and with typical shared servers, it’s not possible to extract the certificates.
Additionally, proxy settings cannot be added to the web server on a shared hosting environment.
While it might be possible to configure a proxy using an .htaccess file on an Apache server, there are limitations—such as the need to have mod_rewrite and mod_proxy enabled.
Furthermore, obtaining FTP access permissions to a web space contracted by another party is often difficult, so this option also seems quite challenging.