We have a project fully configured on our VM. We have a reverse proxy running in front of it with ssl certificate already installed. Access by IP is not allowed. Right now we want to use Cloudflare as CDN solution. I have enabled universal mode and strict mode (as long as the certificate is already installed on the server on a proper domain). When accessing the server I get 403. I suspect that it happens because I use our own certificate on the server, rather than generated by Cloudflare. Is it mandatory to use certs for origin CA generated by Cloudflare?